To provide a camera main body by which an aperture unit is constituted more simply and the manufacturing cost is reduced while securing the necessary strength of the aperture unit itself.

In this camera main body provided with the aperture unit 12 in which an aperture part 3a for photographing and a guide rail 12e for regulating the position of a film in an optical axis direction to the aperture part 3a are formed, a cartridge chamber unit 11 which can be connected to one end of the unit 12 and a spool chamber unit 10 which can be connected to another end of the unit 12, at least either of the film gateways of the units 11 and 10 is provided with a guide part 10e or 11e regulating the position of the width direction of the film fed out from a film cartridge.