A lens barrier driving device that prevents an increase in the number of parts constituting a lens barrier driving mechanism and avoids light leakage from a penetrating portion. A lens barrier is disposed on an object side of a lens and is openable and closable. A transmission member transmits power to a barrier driving member. The barrier driving member opens and closes the lens barrier. A cam member is able to engage with the transmission member. A first member holds the cam member. A second member is provided with a penetrating portion. The penetrating portion is disposed between the lens barrier and the first member. A rib portion of the transmission member penetrates the penetrating portion. A light shielding portion of the transmission member shields a incident light through the penetrating portion.