Substrate monitoring apparatus and substrate monitoring method

This substrate monitoring device is provided with: an imaging unit (27) having a prescribed imaging range; an arranging unit (26a) which arranges the substrate (S) within the imaging range; an irradiation unit (29) which irradiates the substrate (Sc(Se1)) arranged in the imaging range with a laser beam (L), thereby generating reflected light and/or scattered light reflected or scattered by an edge (So(Se1)) of the substrate, forming an image of the edge (Se1) on a light receiving surface of the imaging unit (27); and a monitoring unit which monitors the imaging result of the imaging unit (27).