An image pickup apparatus 30 of the present invention varies optical properties by moving a part of lenses of an objective lens, and includes a solid-state image pickup device unit 46 that is disposed at a rear-end section and that subjects a subject image to photoelectric conversion, a fixed lens frame 36 that retains the objective lens that is disposed in front of the solid-state image pickup device unit, a movable lens frame 38 that retains the part of lenses that moves along a photographing optical axis O inside the lens frame, and an actuator 62 having one end connected to the movable lens frame and that moves the movable lens frame forward and backward. The actuator 62 includes a rigid member 54 provided so as to extend to the vicinity of the rear end at which the solid-state image pickup device unit is disposed and a shape memory alloy 56 that is coupled to the rigid member.