A projector includes a light source, a digital micro-mirror device (DMD), a first prism, and a second prism. The light source emits incident light. The DMD reflects the incident light as an image light. The first prism is disposed between the light source and the DMD. The second prism is disposed between the first prism and the DMD. The first prism includes a first plane, a second plane, and an intermediate portion including a reflecting portion. The incident light is reflected by the reflecting portion and then passes through the second plane. The second prism includes a fourth plane, a fifth plane, and a sixth plane. When the DMD is operated in an OFF-state, the image light is reflected to the sixth plane, and the sixth plane reflects a leakage light of the image light along a predetermined light path away from the prisms.