There is provided a blade drive device including a substrate that has an opening, a front curtain and a rear curtain that are movable along an opening surface of the opening so as to open and close the opening, a front curtain electromagnetic actuator that actuates the front curtain, a rear curtain electromagnetic actuator that actuates the rear curtain, and that is capable of holding the rear curtain at an open position in a state having no power supply, a front curtain locking portion that interlocks with opening and closing operations of the front curtain, a rear curtain locking portion that interlocks with opening and closing operations of the rear curtain, and a blade position holding mechanism that is capable of entry and escape between an entry position which enters each operation trajectory of the front curtain locking portion and the rear curtain locking portion in response to the opening and closing operations of the front curtain and the rear curtain and an escape position escaped from the operation trajectory. At the entry position, the blade position holding mechanism can engage with both the front curtain locking portion and the rear curtain locking portion, thereby regulating the movement of the front curtain and the rear curtain in the closing direction.