The invention provides a metal air battery with improved discharge characteristics compared to conventional ones. This is achieved by a metal air battery including a positive electrode layer, a negative electrode layer, and an electrolyte layer positioned between the positive electrode layer and the negative electrode layer, wherein the positive electrode layer includes an electroconductive material, a binder, and a SiO2 particle, and wherein the SiO2 particle has a specific surface area of 16.7 m2/g or less.