A metal-air battery (1) includes a tubular positive electrode (2) centered on a predetermined central axis (J1), a negative electrode (3) opposing an inner side surface of the positive electrode, and an electrolyte layer (4) disposed between the negative electrode and the positive electrode. The positive electrode includes a positive electrode conductive layer (21), a positive electrode catalyst layer (22), and a positive electrode current collector (24). The positive electrode catalyst layer is formed on the outer side surface of the tubular positive electrode conductive layer centered on the central axis and has lower electrical conductivity than the positive electrode conductive layer. The positive electrode current collector is formed on an area of the outer side surface of the positive electrode conductive layer where the positive electrode catalyst layer does not exist, to be in direct contact with the outer side surface. This structure reduces the electrical resistance between the positive electrode conductive layer and the positive electrode current collector and improves battery performance. Since the thickness in the radial direction of the positive electrode current collector is greater than that of the positive electrode catalyst layer, the positive electrode current collector and a connection terminal can be easily connected to each other.