The Intel 4004 is a 4-bit central processing unit (CPU) released by Intel Corporation in 1971. Sold for US$60, it was the first commercially produced microprocessor, and the first in a long line of Intel CPUs.

The 4004 was the first significant example of large scale integration, showcasing the superiority of the MOS silicon gate technology (SGT). Compared to the incumbent technology, the SGT integrated on the same chip area twice the number of transistors with five times the operating speed. This step-function increase in performance made possible a single-chip CPU, replacing the existing multi-chip CPUs. The innovative 4004 chip design served as a model on how to use the SGT for complex logic and memory circuits, thus accelerating the adoption of the SGT by the worlds semiconductor industry.

The design traces its history to 1969, when Busicom Corp. approached Intel to design a family of seven chips for an electronic calculator, three of which constituted a CPU specialized for making different calculating machines. The CPU was based on data stored on shift-registers and instructions stored on ROM (read only memory). The complexity of the three-chip CPU design led Marcian Hoff to propose a more conventional CPU architecture based on data stored on RAM (random access memory). This architecture was much simpler and more general-purpose and could potentially be integrated into a single chip, thus reducing the cost and improving the speed. Design began in April 1970 under the direction of Federico Faggin aided by Masatoshi Shima who contributed to the architecture and later to the logic design. The first delivery of a fully operational 4004 was in March 1971 to Busicom for its 141-PF printing calculator engineering prototype (now displayed in the Computer History Museum in Mountain View, California). General sales began July 1971.

A number of innovations developed by Faggin while working at Fairchild Semiconductor allowed the 4004 to be produced on a single chip. The main concept was the use of the self-aligned gate, made of polysilicon rather than metal, which allowed the components to be much closer together and work at higher speed. To make the 4004 possible, Faggin also developed the "bootstrap load", considered unfeasible with silicon gate, and the "buried contact" that allowed the silicon gates to be connected directly to the source and drain of the transistors without the use of metal. Together, these innovations doubled the circuit density, and thus halved cost, allowing a single chip to contain 2300 transistors to run five times faster than designs using the previous MOS technology with aluminum gates.

The 4004 design was later improved by Faggin as the Intel 4040 in 1974. The Intel 8008 and 8080 were unrelated designs in spite of the similar naming.

Intel Corporation, stylized as intel, is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is the developer of the x86 series of microprocessors, the processors found in most personal computers (PCs). Incorporated in Delaware, Intel ranked No. 45 in the 2020 Fortune 500 list of the largest United States corporations by total revenue for nearly a decade, from 2007 to 2016 fiscal years.Intel supplies microprocessors for computer system manufacturers such as Acer, Lenovo, HP, and Dell. Intel also manufactures motherboard chipsets, network interface controllers and integrated circuits, flash memory, graphics chips, embedded processors and other devices related to communications and computing.

Intel (integrated and electronics) was founded on July 18, 1968, by semiconductor pioneers Gordon Moore (of Moore's law) and Robert Noyce, and is associated with the executive leadership and vision of Andrew Grove. Intel was a key component of the rise of Silicon Valley as a high-tech center. Noyce was a key inventor of the integrated circuit (microchip). Intel was an early developer of SRAM and DRAM memory chips, which represented the majority of its business until 1981. Although Intel created the world's first commercial microprocessor chip in 1971, it was not until the success of the personal computer (PC) that this became its primary business.

During the 1990s, Intel invested heavily in new microprocessor designs fostering the rapid growth of the computer industry. During this period, Intel became the dominant supplier of microprocessors for PCs and was known for aggressive and anti-competitive tactics in defense of its market position, particularly against Advanced Micro Devices (AMD), as well as a struggle with Microsoft for control over the direction of the PC industry.The Open Source Technology Center at Intel hosts PowerTOP and LatencyTOP, and supports other open-source projects such as Wayland, Mesa, Threading Building Blocks (TBB), and Xen.