According to one embodiment, a semiconductor device includes an internal circuit which is driven by a power supply voltage and is set in one of a first state and a second state in which an amount of current consumed by the internal circuit is greater than in the first state, and a wait control module. The wait control module detects that a state of the internal circuit has transitioned from the first state to the second state, and executes a wait control process of outputting an operation start instruction signal to the internal circuit after passing of a predetermined wait time from the detection of the transition of the state of the internal circuit from the first start to the second state.