The ES is a highly parallel vector supercomputer system of the distributed-memory type, and consisted of 160 processor nodes connected by Fat-Tree Network. Each Processor nodes is a system with a shared memory, consisting of 8 vector-type arithmetic processors, a 128-GB main memory system. The peak performance of each Arthmetic processors is 102.4Gflops. The ES as a whole thus consists of 1280 arithmetic processors with 20 TB of main memory and the theoretical performance of 131Tflops.