To obtain a method and apparatus for detecting and removing remaining shell which are suitable for inspecting whether shell remains or not in the Crustacea such as shrimps and crabs under conditions where shell-peeling operations have been finished.

This apparatus is equipped with an irradiation means 1 for shining light having a specified wavelength on the Crustacea 20 under conditions where shell-peeling operations have been finished, a CCD camera 40 placed to face the Crustacea, a judging means 41 for judging whether Crustacea shell after peeling treatment remains or not on the basis of fluorescence intensity information obtained from images taken by the CCD camera and excluding means 5, 6 and 7 for excluding the Crustacea still having shell on the basis of information from the judging means.