PURPOSE: To secure a large quantity of chips which can be reconstituted to improve the memory capacity and the production yield by constituting a unit memory chip so that the logic circuit part is surrounded with divided memory parts and input/output circuit parts.

CONSTITUTION: A logic circuit part 14 is arranged in the center of a unit memory chip 12 and is surrounded with first and second memory parts 15 and input/ output circuit parts 13. Therefore, the inductance of the unit memory chip 12 avoided as defects by power trouble or the like is reduced, and an influence of induction trouble or the like with a defective memory chip as the noise generation source is reduced as much as possible. Consequently, the use of indefectible unit memory chips is not limited, and unit memory chips are used to reconstitute a wafer scale memory. Thus, the memory capacity is improved to improve the production yield.