An exemplary aspect of an embodiment of the present invention is a semiconductor storage device including a power-on reset generator that outputs a first reset signal in accordance with a level of a power supply voltage, a command decoder that moves to a mode set state in accordance with input of an external control pin and outputs mode set information in accordance with a command input from an address pin, an MRS controller that outputs a mode reset signal (MRSPON signal) in accordance with the mode set information, and a reset circuit that outputs a second reset signal initializing each circuit of an operation control section in accordance with the mode reset signal and the first reset signal.