An image sensing apparatus has a light flux splitter disposed between a lens that focuses light flux of an object image on an image sensing surface and that image sensing surface and that branches the light flux of the object image out of an image sensing light path, a light receiving unit that receives the light flux of the object image branched by the light flux splitter and obtains a signal for focusing control of the lens, and a holding unit that holds the light flux splitter at either an effective position within the image sensing light path or at a retracted position outside the image sensing light path. The image sensing apparatus automatically holds the light flux splitter at either the effective position or the retracted position depending on image sensing conditions.