Method for inspecting membrane electrode structure

A method for inspecting a membrane electrode structure formed by sandwiching an electrolyte membrane between a first electrode layer comprising a first electrode catalyst layer and a first gas diffusion layer, and a second electrode layer comprising a second electrode catalyst layer and a second gas diffusion layer, the method comprising:

• a first step in which a detection medium capable of detecting elements of the first electrode catalyst layer and the second electrode catalyst layer or an element of the electrolyte membrane, and an element of a metal foreign matter is sent such that a focal point is moved along a thickness direction from a side of the first electrode layer to a side of the second electrode layer, thereby obtaining a thickness direction profile of a detection signal;
• and
• a second step in which an analysis unit identifies a thickness direction position of the metal foreign matter, from intensity of the detection signal in the thickness direction profile, and in which the analysis unit identifies thickness direction positions of the first electrode catalyst layer and the second electrode catalyst layer, or a thickness direction position of the electrolyte membrane, from the intensity of the detection signal in the thickness direction profile.