Abstract: Provided are an air electrode having a structure in which an anion exchange membrane and an air electrode catalyst layer are laminated and the anion exchange membrane is disposed in contact with an aqueous alkaline solution; and a metal-air battery, an alkaline fuel cell, and a water electrolysis device each having the air electrode. The air electrode of the present invention can reduce or solve various conventional problems of an air electrode in a metal-air battery, fuel cell, and the like, which use an aqueous alkaline solution as an electrolyte, and can maintain high performance for a long period of time.