[Problem]To provide a membrane and electrode assembly comprising a catalyst layer that improves water holding properties and exhibits high power generation characteristics even in low humidified conditions without inhibiting removal of the water generated by the electrode reaction, etc. and its manufacturing method.[Solution]The membrane and electrode assembly produced by sandwiching a polymer electrolyte membrane between a pair of catalyst layers is provided, in which the catalyst layer comprises a polymer electrolyte and particles carrying a catalyst material, and in which the proportion of the polymer electrolyte expressed by {(mass of polymer electrolyte)/(mass of particles in particles carrying catalyst material)} in the catalyst layer is decreased toward the polymer electrolyte membrane (the inside) from the surface of the catalyst layer (the outside).