To provide a metal/resin complex having strength, hardness and the like equal to those of a metal part.

After a resin composition containing a resin and a crosslinking aid for the resin is molded and the required surface of the resin molded product is treated, a metal layer is formed at least to a part of the surface of the resin molded product and the resin is crosslinked by the irradiation with radiation to obtain a crosslinked resin molded product which is, in turn, heat-treated and annealed to manufacture the metal/resin complex. This metal/resin complex has a tensile strength of 200 MPa or above, a bending elastic modulus of 10 GPa or above and a Vickers hardness of 100 Hv or above.