To provide a blade drive device capable of suppressing operation failures due to the leakage flux. The blade drive device 1 attached to a camera module including a lens and a lens drive device 60 having plural permanent magnets 61 arranged with gaps around an optical axis P of the lens in an annular manner so as to overlap the camera module in an axial direction of the optical axis P, which includes a lower plate 2 having an opening 4 formed around the optical axis P, blades 20 regulating the opening 4 and respective actuators 10A, 10B arranged in the lower plate 2 and driving the blades 20. Each of respective actuators 10A, 10B is arranged in a position corresponding to a gap between a pair of adjacent permanent magnets 61 seen from the axial direction.