A method of manufacturing a metal microstructure (1) by using a resin mold (13). In order to provide a method in which a mild manufacturing condition which causes less damage to the resin mold (13) can be set and the high-precision metal microstructure (1) can be mass-produced by uniform electroforming, the method of manufacturing the metal microstructure (1) according to the present invention includes the steps of: fixing on a conductive substrate (11) the resin mold (13) having a vacant portion penetrating in the direction of thickness, by interposing a photosensitive polymer (12) having a chemical composition changed by an electron beam, ultraviolet radiation or visible radiation so as to form a layered structure (2) having the resin mold (13); exposing the layered structure (2) having the resin mold (13) to an electron beam, ultraviolet radiation or visible radiation; removing an exposed photosensitive polymer (12c) existing at the vacant portion of the resin mold (13); and filling with a metal (14) the vacant portion of the layered structure (2) having the resin mold (13) by electroforming.