An additive manufacturing apparatus in which a streak in a manufacturing direction is difficult to be made on the surface of a product manufactured object in a boundary region of projection regions of exposure images is provided. In this apparatus, a vessel holds a photosetting liquid resin material, a first projector makes a first exposure image incident from an incident surface and projects it into the resin material, a second projector makes a second exposure image, continuous with the first exposure image, incident from the incident surface and projects it into the resin material, and a controlling unit adjusts on a projection surface a boundary region between a first projection image obtained by projecting the first exposure image by the first projector and a second projection image obtained by projecting the second exposure image by the second projector.