An image sensing apparatus having a large depth of focus (DOF) and being compact in size is provided. The image sensing apparatus includes a plurality of light sources that shines light beams on an illumination portion of a document; a first mirror that receives incident light scattered by reflection from the document, to reflect the scattered light in the secondary scan direction; a plurality of first concaved aspheric mirrors that collimates light beams from the first mirror, to reflect therefrom the collimated light beams as substantially collimated light fluxes; an aperture mirror that reflects therefrom the light beams from the respective first aspheric mirrors, through apertures each having a light-shielded portion formed therearound and selectively passing the light beams therethrough; a plurality of second concaved aspheric mirrors that receives the light beams incident from the respective aperture mirror, to reflect the incident light beams as converging light beams; a second mirror that reflects the light beams in a direction perpendicular to the surface of the document, disposed on a path of the light beams to be converged by means of the second aspheric mirrors; a plurality of light receivers each having a light-receiving area that receives the light beams from the second mirrors, to form images according to the light beams from the respective apertures; and a casing where the first and second aspheric mirrors are disposed on a first side of the casing in the secondary scan direction, and the aperture mirror is disposed on a second side thereof in the secondary scan direction.