A bonded body is provided in which an aluminum alloy member formed from an aluminum alloy, and a metal member formed from copper, nickel, or silver are bonded to each other. The aluminum alloy member is constituted by an aluminum alloy in which a concentration of Si is in a range of 1 mass % to 25 mass %. The aluminum alloy member and the metal member are subjected to solid-phase diffusion bonding. A compound layer, which is formed through diffusion of Al of the aluminum alloy member and a metal element of the metal member, is provided at a bonding interface between the aluminum alloy member and the metal member. A Mg-concentrated layer, in which a concentration of Mg is to 3 mass % or greater, is formed at the inside of the compound layer, and the thickness of the Mg-concentrated layer is in a range of 1 μm to 30 μm.