A control device for periodic flash photographies is provided with an actuation timing setting circuit in which actuation timings of a camera are manually set and a timer control circuit which generates a first signal at every set actuation timing and a second signal a given period of time before every set actuation timing. The first signal is applied to a camera release electromagnet of the camera for a camera release operation. The second signal is applied to a voltage booster circuit of an electronic flash device or an external power source for an electronic flash device, so that a control transistor of the voltage booster circuit is made conductive by the second signal to supply current to the base of an oscillation transistor of the voltage booster circuit for the oscillation thereof, whereby the voltage booster circuit generates a high voltage applied to a main capacitor of the electronic flash device for the charging thereof. The generation of the second signal may stop after every set actuation timing, e.g. at the time of closure of a synchronous switch of the camera for firing the electronic flash tube.