A shake preventing apparatus comprises a shaking sensor for detecting a shake, a shaking preventive optical system for preventing an image shake by this optical system being shifted in a direction substantially orthogonal to an optical axis of a principal optical system, motors for driving this shaking preventive optical system to prevent the shake detected by the shaking sensor, photo interrupters for detecting a shift position of the shaking preventive optical system and a control circuit for controlling the motors on the basis of detection signals from the photo interrupters. The photo interrupters are disposed within a range so as not to exceed a thickness of the shaking preventive optical system in an optical-axis direction.