A flash device includes at least one light emitting unit is attachable to a plurality of connection portions. A shielding portion shields the connection portion without an attached light emitting unit. A capacitor accumulates an electric charges and is charged by a charging circuit. A control circuit includes judges both (1) whether or not all the plurality of connection portions are shielded and (2) whether or not the light emitting unit is attached to at least one of the plurality of connection portions, and permits the capacitor to be charged if both all the connection portions are shielded and the light emitting unit is attached to at least one of the plurality of connection portions.