PROBLEM TO BE SOLVED: To provide a using method in which output characteristic or the like is stabilized in a metal air secondary battery.SOLUTION: Disclosed is a method for using a metal air secondary battery. The metal air secondary battery includes: a hydroxide ion conductive solid electrolyte; an air electrode provided as a positive electrode in close contact with one surface side of a solid electrolyte; and a metal negative electrode provided on the other side of the solid electrolyte. The method for using the metal air secondary battery includes controlling temperature of the metal air secondary battery and/or humidity in the air supplied to the air electrode substantially uniformly.
