A method of manufacturing a metal microstructure by using a resin mold. In order to provide a method in which a mild manufacturing condition which causes less damage to the resin mold can be set and the high-precision metal microstructure can be mass-produced by uniform electroforming, the method of manufacturing the metal microstructure according to the present invention includes the steps of: fixing on a conductive substrate the resin mold having a vacant portion penetrating in the direction of thickness, by interposing a photosensitive polymer having a chemical composition changed by an electron beam, ultraviolet radiation or visible radiation so as to form a layered structure having the resin mold; exposing the layered structure having the resin mold to an electron beam, ultraviolet radiation or visible radiation; removing an exposed photosensitive polymer existing at the vacant portion of the resin mold; and filling with a metal the vacant portion of the layered structure having the resin mold by electroforming.