To improve the assembly workability in manufacturing a camera with a diaphragm selecting device.

A lens unit 52 selects a diaphragm by inserting and removing a small diaphragm opening 62a of a movable diaphragm plate 62 fixed to a diaphragm lever 65 onto an from an optical axis PL. A lens unit 52 is attached to the prescribed position in front of a dark box base section 50. A diaphragm selector lever 67, a stopper 69, a solenoid 79, etc., are arranged at a substrate 39. The diaphragm selector lever 67 is supported by a boss 55b and turns according to the on/off of the solenoid 70. The substrate 39 is positioned by engagement of the boss 55b with a fitting hole 11c in such a manner that the diaphragm selector lever 67 is arranged on the same plane as the plane of the moving route of an arm 65b. When the diaphragm selector lever 67 turns clockwise, the arm 65b is thrust to turn the movable diaphragm plate 62 counterclockwise, thereby selecting the diaphragm. The diaphragm selecting device is functioned simply by building the lens unit 52 and the substrate 39 in the manner described above.