PURPOSE: To provide an exposure controller for a disposable underwater camera.

CONSTITUTION: In the camera (1) by which an underwater photograph and a daylight photograph can be taken, the exposure controller (24) can be automatically controlled with an exposure parameter as an increased hydraulic function. Preferably, a pressure detecting means (71) is mechanically connected to a double blade diaphragm and when the camera (1) starts to sink in the water, the aperture (69) of a lens is consecutively increased.