Abstract: A low cost computer is suitable for small size configuration. Casings 4 and 32 are formed by aluminum, which is a heat radiating material, and CPUs 6 and 36, hard disk devices 8 and 38, control ICs 40 and 42 and a memory IC are mounted on the casing 4 directly or by the heat radiating material. The casings 4 and 32 are utilized as heat radiators, thereby making the entire computer a smaller size.