A substrate is provided on which wires can be formed satisfactorily using a dispersion liquid of metal microparticles without causing disconnection or short circuit. The wiring substrate comprises a substrate, an organic membrane formed on the substrate, and a metal wire formed on the organic membrane. An arithmetic mean deviation Ra of the profile of the surface of the organic membrane where the metal wire is formed is not less than 60 nm and not more than 5×10−2D, where D is the width of the metal wire. The contact angle with respect to water on the surface of the organic membrane where the metal wire is formed is not less than 110°.