Abstract: The construction of Earth Simulator was much more than simply delivering a high amount of TFLOPS in a Single System Image. This construction meant a breakthrough in the hardware engineering and sofware development.The practical result was the delivery of 1st world´s single chip vector processor. The technology to accommodate large amount of circuits in a small chip demanded the early adoption of 0.15 uprocess which can be represented as if printing 140 lines in the size of a human hair. Other formidable achiviements are the cooling system, CPU-memory cabling and Inter-node. In perfect harmony with the hardware techology, the set of softwares allowed this 40TFLOPS system to reach 35.86 GFLOPS with LINPACK benchmark and the outstanding mark of 26TFLOPS with a AGCM, a real application.