Your vote on this answer has already been received
The 4004 is considered the first microprocessor. The architecture and specifications of the 4004 were the results of the interaction of Intels Hoff with Stanley Mazor, a software engineer reporting to Hoff, and with Busicom engineer Masatoshi Shima. In April 1970 Intel hired Federico Faggin to lead the design of the four-chip set. Faggin, who originally developed the silicon gate technology (SGT) in 1968 at Fairchild Semiconductor (and also designed the worlds first commercial integrated circuit using SGT the Fairchild 3708), had the correct background to lead the project since it was the SGT to make possible the design of a CPU into a single chip with the proper speed, power dissipation and cost. Faggin also developed the new methodology for random logic design, based on silicon gate, that made the 4004 possible. Production units of the 4004 were first delivered to Busicom in March 1971, and shipped to other customers in late 1971.