A semiconductor device includes a boot-up start signal generation unit configured to generate a boot-up start signal which is enabled in synchronization with a time at which a preset delay period has passed from a time point at which an initialization signal is enabled after a power-up period is ended, and a boot-up period signal generation unit configured to generate a boot-up period signal which is enabled according to a set pulse generated in synchronization with a time point at which the boot-up start signal is enabled.