A projector includes a light source, a projection component, a photodetector, and an inclination calculator. The light source outputs light. The projection component projects an image on a projection surface by scanning the light outputted by the light source at an angle to the projection surface. The photodetector detects, as a reflected light, the light that has been scanned by the projection component and reflected by a detection object within a light detection range of the photodetector. The light detection range is set to a predetermined range in a direction perpendicular to the projection surface. The inclination calculator calculates an inclination angle of the detection object in a sub-scanning direction of the light based on a position of the detection object on the projection surface and a number of times the reflected light is detected while scanning in the sub-scanning direction.