Laminate, metal plating solution, and manufacturing process of laminate

A laminate comprising:

• a substrate;
• and
• a laminated film portion with metal films laminated in two or more layers, wherein
• the laminate has an interface layer between each two adjacent ones of the metal films, wherein only the interface layer contains S,
• the laminated film portion contains a first metal element as a principal component, the first metal element is Ni and a second metal element is a metal element of smaller cohesive energy than that of the first metal element,
• a concentration of the first metal element in the metal films is 90 at % or higher, and a concentration of the second metal element in the metal films is 1 at % or less,
• the metals films contain at least one of P or B at a concentration in the metal films 3 at % or higher based on the concentration of the first metal element in the metal films, and
• the second metal element contained in the interface layer is at a content ratio higher than that of the second metal element contained in each of the adjacent metal films.