The present invention provides a plating method and a plating apparatus which can securely form a metal film (protective film) by electroless plating on the exposed surfaces of a base metal, such as interconnects without the formation of voids in the base metal. The plating method including providing a semiconductor device having an embedded interconnect structure, carrying out pretreatment of interconnects with a pre-treatment liquid containing a surface activating agent for the interconnects, carrying out catalytic treatment of the interconnects with a catalytic treatment liquid containing catalyst metal ions and an excessive etching inhibitor for the interconnects, and forming a protective film by electroless plating selectively on the surfaces of the interconnects.