Provided is a plating film that can exhibit a high gloss and a low contact resistance value. The plating film according to an embodiment of the present invention is a plating film including a noble metal matrix and nanodiamond particles dispersed in the noble metal matrix. The plating film according to an embodiment of the present invention preferably has a gloss at an incident angle of 60° of not less than 250 GU and/or a contact resistance value at a load of 50 gf of not greater than 1 mΩ, and a difference between a contact resistance value at a load of 50 gf and a contact resistance value at a load of 5 gf of not greater than 5 mΩ. The nanodiamond particles are preferably nanodiamond particles including a surface-modifying group containing a sterically repulsive group and particularly preferably nanodiamond particles including a surface-modifying group containing a polyglycerol chain.