An inspection object imaging apparatus comprising: a light source configured to produce a light beam belonging to an infrared wavelength band, a spread half-angle of the light beam on a surface of an inspection object being 20 times or less a minimum inclination of a surface to be imaged; a projection optical system configured to project the light beam on the surface of the inspection object at a predetermined projection angle; and an imaging unit configured to image the light beam reflected at the surface of the inspection object, wherein the imaging unit includes an imaging optical system including at least one convex lens, configured to condense reflected light from the surface of the inspection object, and including a branching optical element that branches the reflected light to two different directions, and a first image sensor and a second image sensor each configured to image the reflected light that has passed through the imaging optical system, wherein the first image sensor is provided on the inspection object side with respect to a position of the imaging optical system that is conjugate with the surface of the inspection object, along an optical axis of the reflected light, and the second image sensor is provided on the reflected-light travel direction side with respect to the conjugate position of the imaging optical system, along an optical axis of the reflected light, characterised in that the inspection object is positioned on a surface of a roll having a predetermined curvature and is in corresponding curved state, and the projection optical system and the imaging optical system include a cylindrical lens whose focus coincides with a rotation center axis of the roll. a light source configured to produce a light beam belonging to an infrared wavelength band, a spread half-angle of the light beam on a surface of an inspection object being 20 times or less a minimum inclination of a surface to be imaged; a projection optical system configured to project the light beam on the surface of the inspection object at a predetermined projection angle; and an imaging unit configured to image the light beam reflected at the surface of the inspection object, wherein the imaging unit includes an imaging optical system including at least one convex lens, configured to condense reflected light from the surface of the inspection object, and including a branching optical element that branches the reflected light to two different directions, and a first image sensor and a second image sensor each configured to image the reflected light that has passed through the imaging optical system, wherein the first image sensor is provided on the inspection object side with respect to a position of the imaging optical system that is conjugate with the surface of the inspection object, along an optical axis of the reflected light, and the second image sensor is provided on the reflected-light travel direction side with respect to the conjugate position of the imaging optical system, along an optical axis of the reflected light, characterised in that the inspection object is positioned on a surface of a roll having a predetermined curvature and is in corresponding curved state, and an imaging optical system including at least one convex lens, configured to condense reflected light from the surface of the inspection object, and including a branching optical element that branches the reflected light to two different directions, and a first image sensor and a second image sensor each configured to image the reflected light that has passed through the imaging optical system, wherein the first image sensor is provided on the inspection object side with respect to a position of the imaging optical system that is conjugate with the surface of the inspection object, along an optical axis of the reflected light, and the second image sensor is provided on the reflected-light travel direction side with respect to the conjugate position of the imaging optical system, along an optical axis of the reflected light, characterised in that the inspection object is positioned on a surface of a roll having a predetermined curvature and is in corresponding curved state, and the projection optical system and the imaging optical system include a cylindrical lens whose focus coincides with a rotation center axis of the roll.