PURPOSE: To provide a semiconductor device of high package density including a plurality of chips provided with a voltage stabilizing circuit for supplying a current to a plurality of chips and a temperature control circuit for controlling a temperature of a plurality of chips.

CONSTITUTION: A semiconductor device is provided with a large chip 1 wherein active circuits 1a, 1b are formed, a multilayer wiring layer 3 formed on the large chip 1 and a plurality of small chips 2a, to 2f joined to the multilayer wiring layer 3, and the multilayer wiring layer 3 is composed of a wiring layer connected to the active circuits 1a, 1b and a wiring layer connected to a plurality of small chips 2a, to 2f. The active circuits includes a voltage stabilizing circuit 1a which supplies power to a plurality of small chips 2a to 2f. The active circuit also includes a temperature control circuit 1b which controls a temperature of a plurality of small chips 2a to 2f.