An inspection apparatus for a sheet of paper subjected to a process to impart a translucent property such as a “watermark” or a “security window” includes: an inspection cylinder in which a surface facing the sheet of paper is provided with a luminescence-producing portion; UV-LED illuminators which irradiate the sheet of paper with light containing the ultraviolet rays; a color camera which images the sheet of paper; an ultraviolet cut filter which eliminates the ultraviolet rays in the light emitted from the UV-LED illuminators and reflected off the sheet of paper as well as the luminescence-producing portion and makes only the light having wavelengths longer than wavelengths of the ultraviolet rays incident on the color camera; and a control device which determines appropriateness of a processed portion on the sheet of paper having the translucent property on the basis of luminescence in a visible light range produced by the luminescence-producing portion and made incident on the color camera.