To enable to polish the edge surface of a resin sealed sample precisely and fast by arranging a pair of arm parts that are indicated with scales and arranged on both sides of the sample in parallel and providing with a groin that connects each of one side end of the arms.

A measuring instrument 11 for polishing the edges surface of a sample as a jig in the method of the polishing the edge surface of a sample is formed to be C shape on a planar view. The measuring instrument 11 is arranged with a pair of arm parts 13a and 13b and indicated with scales 14 that work as standards for polishing the edge surface B1 of a sample Bd. A parts of arms are arranged in parallel with the sample Bd on both sides of it when the measuring instrument 11 is resin sealed with the sample Bd. Each of the one side edge of both arms 13a and 13b is connected by a groin part 15. When the sample Bd is resin sealed for polishing, the measuring instrument 11 is resin sealed together with the sample Bd and the predetermined polishing position of the sample Bd is confirmed with it. With this, the confirmation of the smoothness of the polishing surface is not necessary by the finishing step of polishing the sample Bd so that the worktime can be reduced drastically.