[Problem] To enable the simplified release of metal components from molds when manufacturing metal components. [Solution] A release film (16) containing a compound represented by X-L-Si-(O-R)3 is formed on a relief pattern on a casting mold (20), a catalyst for electroless plating is applied to the release film (16), and a conducting membrane (14) for electrocasting is formed on the release film (16) by electroless plating using the catalyst. A metal material (12) is deposited on the conducting membrane (14) by electrocasting using the conducting membrane (14), and the deposited metal material (12) is released from the casting mold (20). X is a group having an aromatic ring, L is a C1-10 connecting group having at least one among a sulfur atom, an oxygen atom or a nitrogen atom, and R is a hydrogen atom or a C1-4 alkyl group.
