A method for producing a metal-resin composite includes a coating step, an assembling step, and a heating step. The coating step coats at least part of the outer periphery of a solid metal first member with a foaming resin and a non-foaming resin. The assembling step disposes the first member within a hollow metal second member. The heating step heats an assembly of the second member within which the first member coated with the foaming resin and the non-foaming resin with the axes of the first member and the second member extending in the horizontal direction, and thus foams the foaming resin between the first member and the second member.