<p>A blade drive device (1) comprises: a base plate (10) having a light path opening (11); a blade (30) having openings (31-33); an electromagnetic actuator (50a) for rocking the blade (30) to advance and retract the blade (30) relative to the light path opening (11); and an electromagnetic actuator (50b) for changing the position of the point of support about which the blade (30) rocks relative to the base plate (10). The electromagnetic actuator (50a) includes a rotor (51a) and a transmitting section (58a) which transmits rotation of the rotor (51a) to the blade (30). The electromagnetic actuator (50b) includes a rotor (51b) and a transmitting section (58b) which transmits rotation of the rotor (51b) to the blade (30). The blade (30) includes a cam groove (19a) engaging with the transmitting section (58a), and also includes a fitting hole (19b) in which the transmitting section (58b) slidably fits.</p>
