It is an object of the present invention to provide an electronic component manufacturing method, capable of suppressing reduction in a trench opening and suppressing diffusion of a metal film embedded in a trench. An embodiment of the present invention is an electronic component manufacturing method, including the steps of: forming a first electrode constituting layer (e.g., a TiAl film) in a recess (e.g., a trench) formed in a workpiece; forming an ultrathin barrier layer (e.g., a TiAlN film) by forming a nitride layer by plasma-nitriding a surface of the first electrode constituting layer; and forming a second electrode constituting layer (e.g., an Al wiring layer) on the ultrathin barrier layer.