There is disclosed a mirror rocking member for an optical deflector. The optical deflector comprises the mirror rocking member for deflecting light, and a driver for driving the member. The mirror rocking member comprises a movable plate having a reflective surface, an elastic member for rockably supporting the movable plate, and a support for supporting the elastic member. The movable plate has an electric element, which constitutes a part of the driver. The movable plate includes a first portion having the reflective surface, and a second portion including an electric element. The first portion has a reflective-surface forming surface with the reflective surface formed thereon, the second portion has an electric-element forming surface with the electric element formed thereon, and the reflective-surface forming surface has an area smaller than an area of the electric-element forming surface.