A projection apparatus includes a light source, a light modulation portion, a first mirror, a second mirror, a third mirror, a fourth mirror, and a projection optical system. The light source performs irradiation with light. The light modulation portion modulates the light from the light source. The first mirror, the second mirror, the third mirror, and the fourth mirror reflect an optical image modulated by the light modulation portion. The projection optical system projects the optical image reflected by the first mirror, the second mirror, the third mirror, and the fourth mirror to a projection surface of a projection target object. The first mirror, the second mirror, the third mirror, and the fourth mirror are arranged between the light modulation portion and the projection optical system.