To inspect nonuniformity of color accurately and reliably by removing the shading component effected by the characteristics of a color camera.

At the angle or position of a color camera 3 for picking up the image of a glass substrate 1 for liquid crystal display is altered under control of an image pickup altering section 26. Image of the glass substrate 1 is picked up while dividing into a plurality of sections. First to third divided image data are then combined at an image combining section 28 to produce the color image data of the entire glass substrate 1 and the nonuniformity of color is inspected for the glass substrate 1 based on the color image data.