A camera, in which it is possible to adjust the position of two mirrors easily for striking a balance between the focus detection performances in an optical viewfinder state and an electronic image display state. The optical apparatus includes a first mirror movable between a first position for an optical viewfinder and a second position for focus detection, a second mirror movable between a third position for focus detection and a fourth position where a light flux is not led to the second mirror, a first positioning member for positioning the first mirror at the second position, and a second positioning member for positioning the second mirror at the third position. The second positioning member is a member independent of the first positioning member.