Provided is a metal-air battery and a method of using the same that make it possible to simplify replacement work while also sustaining high output effectively. The metal-air battery includes a cell unit provided with a plurality of metal-air battery cells in parallel, each metal-air battery cell being configured to include a metal electrode, an air electrode disposed facing the metal electrode, and a housing that supports the metal electrode and the air electrode. The metal-air battery also includes handles for example that act as a first replacing means enabling the replacement of the entire cell unit. With this arrangement, it is possible to simplify replacement work while also sustaining high output effectively.