The substrate for a printed circuit board according to an embodiment of the present invention includes a base film having insulating properties, and a metal layer stacked on at least one surface of the base film, in which the base film includes a portion where a transition metal in group 10 of the periodic table is present. The transition metal in group 10 is preferably nickel or palladium. The portion where the transition metal in group 10 is present preferably includes a region having an average thickness of 500 nm and extending from an interface with the metal layer.