Provided is a metal-air battery including a cathode having a space which may be filled with a metal oxide formed during a discharge of the metal-air battery and thus having improved energy density and lifespan. The cathode for the metal-air battery includes a plurality of cathode materials, a plurality of electrolyte films disposed on surfaces of the plurality of cathode materials, and a plurality of spaces which are not occupied by the plurality of cathode materials and the plurality of electrolyte films. A volume of the plurality of spaces may be greater than or equal to a maximum space of a metal oxide formed during a discharge of the metal-air battery.