According to one embodiment, an imaging apparatus includes a light source for illumination, a stage on which an imaging object illuminated by illumination light from the light source is to be placed, a critical illumination optical system configured to supply the illumination light to the imaging object placed on the stage, and to have a greater magnification in a first axis direction than in a second axis direction, an imaging optical system configured to form an image of the imaging object placed on the stage and illuminated using the critical illumination optical system, and a detector configured to detect the image of the imaging object formed by the imaging optical system, and to have a detection area longer in the first axis direction than in the second axis direction.