PURPOSE: To prevent the rear cover from being opened carelessly when a film is not rewound, by using outputs of a switch, which is operated by the opening operation of the rear cover, and a switch, which detects a film, to operate a buzzer.

CONSTITUTION: A clamping pawl 5 consisting of a plate member is supported in a long hole 500 vertically slidably by a pin 6, and a rear cover 4 and an engaging part 501 are engaged with each other, and a camera body and the rear cover 4 are fixed. A switch SL for alarm is operated by an operating piece 507 of the clamping pawl 5, and a film detecting switch SF and a buzzer B are arranged in series. When a clamping pawl 5 is depressed with a film loaded and the rear cover 4 closed, the switch SL is turned off, and the switch SF detects the existence of the film, and a transistor Tr is turned on to operate the buzzer B. Since the cover is not opened yet in this state, the film which is not rewound is prevented from being exposed to the external light if the depression is stopped.