A holding apparatus for a projector includes a frame, a connection body, a telescopic device, and a bracket. The frame is fixed to a surface. One end of the connection body is connected to the frame. The telescopic device is fixed to the other end of the connection body opposite to the frame along an extending direction of the connection body. The telescopic device includes a moving unit movable along a first direction perpendicular to the extending direction of the connection body. The moving unit is connected to a detecting module. The bracket has a first end connected to the frame and a second end for connecting the projector. The second end is disposed opposite to the surface and extends along the first direction.