A projection optical projects from a first image plane on a reducing side onto a second image plane on a magnifying side includes: a first optical system with a plurality of lenses that forms a first intermediate image on a first side of an optical axis inside the first optical system by light that is incident from the reducing side, into a second intermediate image on a second side of the optical axis at a position closer to the magnifying side than the first optical system. A second optical system includes a first reflective surface with positive power that is positioned closer to the magnifying side than the second intermediate image. The first optical system includes an intermediate lens. The first intermediate image is formed to be inclined to be closer to the reducing side as a distance from the optical axis increases so as to straddle the intermediate lens.