For generating an image for inspection of a substrate, a camera is provided above this substrate with an optical axis orienting downward and a plurality of multi-colored light emitting members are set around the optical axis of the camera so as to be within a specified angular range with respect to a target area on the substrate. The camera is operated to generate an image of the target area for inspection while switched-on conditions of these light emitting members are being controlled such that the colors and angles of light illuminating this target area are varied according to a specified kind of the purpose of this inspection.