A projection apparatus comprising a projection unit provided with an optical system that projects an image, a housing that houses the projection unit, a first surface, provided at the housing, that functions as a distance reference surface that defines a distance from a projection window that the housing is provided with to a projection surface that projects the image and as a first placement surface used when setting the housing, and a second surface, provided at the housing, that perpendicularly intersects the first surface and functions as a second placement surface when setting the housing is provided.