Method and apparatus for measuring thickness of electrolyte membrane

An electrolyte membrane thickness measurement apparatus for measuring a thickness of an electrolyte membrane in a membrane electrode assembly containing a first electrode, a second electrode, and the electrolyte membrane sandwiched therebetween, the electrolyte membrane containing a solid polymer, the first electrode including a first electrode catalyst layer containing a metal catalyst, the second electrode including a second electrode catalyst layer containing a metal catalyst, the electrolyte membrane thickness measurement apparatus comprising:

• a detecting medium supplying portion configured to supply a detecting medium to detect the metal catalyst in the first electrode catalyst layer and the second electrode catalyst layer, to the membrane electrode assembly in a thickness direction from the first electrode catalyst layer to the second electrode catalyst layer;
• a detecting portion configured to detect the metal catalyst to obtain a thickness direction profile of a detection signal;
• and
• an analyzing unit configured to determine a first inflection point and a second inflection point based on an intensity of the detection signal in the thickness direction profile obtained by the detecting portion, and evaluate a distance between the first inflection point and the second inflection point as the thickness of the electrolyte membrane.