MEMBRANE ELECTRODE ASSEMBLY, ELECTROCHEMICAL DEVICE, AND ELECTROCHEMICAL SYSTEM

A membrane electrode assembly according to the present disclosure includes an electrolyte membrane containing a solid electrolyte and a first electrode bonded to the electrolyte membrane, wherein the solid electrolyte is a compound represented by the composition formula (1): BaZrMO, M in the composition formula (1) is at least one element selected from the group consisting of Sc, Er, Ho, Dy, Gd, Y, In, Tm, Yb, and Lu, and 0