To provide an image quality inspecting device the entire cost of which is reduced by reducing costs of components and the running cost of which is reduced, and an image quality inspecting method.

In the image quality inspecting device, the inspection is conducted by processing the image of a plate to be inspected, which is photographed with a camera in a lighted state. It is equipped with: a camera obscura which is shielded from external light so as to photograph the image of the plate to be inspected; the camera which is arranged inside the camera obscura and from which the shutter function is removed; and a light source which is arranged inside the camera obscura, is lighted only during a shutter time period, and illuminates the inspection surface of the plate to be inspected. Furthermore, a setting section to set the lighted time period and light quantity of the light source to be values corresponding to the plate to be inspected is arranged. In the image quality inspecting device, the plate to be inspected is arranged in the camera obscura shielded from the external light oppositely to the camera from which the shutter function has been removed, and the inspection surface of the plate to be inspected is photographed with the camera by turning on the light source only during the shutter time period of the camera and illuminating the inspection surface of the plate to be inspected.