A method of producing a displacement plating precursor, including a deposition step of depositing a Cu layer on a surface of a core particle formed of Pt or a Pt alloy by contacting a Cu ion-containing acidic aqueous solution with at least a portion of a Cu electrode, and contacting the Cu electrode with the core particle or with a composite, in which the core particle is supported on an electroconductive support, within the acidic aqueous solution or outside the acidic aqueous solution, and moreover contacting the core particle with the acidic aqueous solution under an inert gas atmosphere.