A head-up display includes light source elements arranged in a first direction, a first lens which takes in from an incident surface light emitted from the light source elements and emits the light from an emission surface. A diffusion member is disposed on a side of the emission surface of the first lens. A spatial light modulation element takes in from an incident surface the light having been emitted from the light source elements and having passed through the first lens and the diffusion member, modulates the taken-in light in accordance with image information, and emits the modulated light from an emission surface. An optical element reflects light emitted from spatial light modulation element. The first lens changes an optical path of light emitted from each of the light source elements such that it reaches the same point on the incident surface of the spatial light modulation element.