Provided is a strobe unit compatible with both a camera that has a synchro switch that does not cause chattering and that can achieve a large number of times of flash photography per unit time and a camera that has a synchro switch whose chattering time is long or short. The strobe unit comprises: a chattering preventing unit that is connected to a flashlight emission initiating unit; a checking unit that checks the type of synchro switch included in an image sensing apparatus, which is connected to the strobe unit via a communication terminal, through transfer of information with the image sensing apparatus; and a control unit that controls the chattering preventing unit according to the result of checking performed by the checking unit.