Method of producing metal film

A method of producing a metal film, comprising:

• the organic film forming step of applying, onto a substrate or a film, an underlayer composition containing an addition polymerizable compound having three or more reactive groups, an addition polymerizable compound having acid groups, and an addition polymerizable compound having hydrophilic functional groups and polymerizing the composition, to form an organic film;
• the metal salt producing step of processing the organic film with an aqueous solution containing metal (M1) ions, to convert the acid groups to a metal (M1) salt;
• the metal fixing step of processing the organic film processed with the aqueous solution containing metal (M1) ions with an aqueous metal (M2) ion solution containing metal (M2) ions having lower ionicity than the metal (M1) ions, to convert the metal (M1) salt of the acid groups to a metal (M2) salt;
• and
• the reduction step of reducing the metal (M2) ions, to form a metal film on a surface of the organic film,
• wherein either the underlayer composition is polymerized under ultraviolet radiation using a mask, followed by removal of unreacted monomer, in the organic film forming step or the metal (M2) ions are reduced under ultraviolet radiation using a mask in the reduction step, to form the metal film in a pattern.