A projection apparatus having a light modulation element includes a main body; an optical unit that is rotatably supported by the main body and includes a projection optical system for projecting the spatially modulated light onto the projection surface, a first rotation member rotatably supported to the main body and a second rotation member rotatably supported to the first rotation member; a first sensor; a second sensor; a controller; and a regulation mechanism, and the regulation mechanism includes a moving member that is movable between a regulation position for regulating the rotation and a regulation release position for releasing the regulating of the rotation, and fixes the moving member at the regulation position in a case where the controller determines that the first rotation member and the second rotation member are in the predetermined specific rotation state.