To provide a blade driving device for cameras linearly reciprocating two blades in the opposite directions and, even if a whole device is slimly constituted, favorably operating the blades without forming the blades elongated in an operation direction.

Shutter blades 4 and 5 are formed with cam grooves 4d and 5d. An accessory plate 6 is disposed in layers, near a region where the cam grooves 4d and 5d are formed, between the shutter blades 4 and 5. A driving member 3 integrated with an output shaft 2a of a stepping motor 2 allows driving pins 3c and 3d provided at the tip ends of arm parts 3a and 3b to insert into a blade chamber, the driving pin 3c is inserted into the cam groove 4d of the shutter blade 4 and one hole 6a of the accessory plate 6, and the driving pin 3d is inserted into the other hole 6b of the accessory plate 6 and the cam groove 5d of the shutter blade 5.