Japan Aerospace Exploration Agency has introduced a new terascale SMP-cluster-type parallel supercomputer system as Numerical Simulator III (NS-III) for aerospace science and engineering research purposes. The system has been in full operation since October 2002. This system is using Fujitsu PRIMEPOWER HPC2500 as main compute engine; it has computing capability 9.3 tflop/s peak performance and 3.6 TB of user memory, with about 1,800 scalar processors for computation. It has mass storage consisting of 57 TB disk storage and a 620 TB tape library. A visualization system is tightly integrated with the computation system. In this paper, we give a brief review for the history of the Numerical Simulator first, then we describe the system configuration in detail as well as the requirement and design of the NS-III. Next, we present the performance evaluation results of the Fujitsu PRIMEPOWER HPC2500 system both for micro- and kernel-benchmarks and aerospace CFD applications used at JAXA, and finally we will discuss how we use the system efficiently.