A sophisticated semiconductor device is provided. A semiconductor device including an IPD chip and an MCU chip which are included in one package. The IPD chip includes: a power transistor that drives an external load; a gate drive circuit that drives the power transistor; and a protection circuit that protects the power transistor from having a breakdown. The MCU chip includes an arithmetic processing unit that performs arithmetic processing based on detected data output from the protection circuit, and a storage unit that stores a program for the arithmetic processing unit. The MCU chip has a function of controlling operation of the power transistor according to the detected data.