A wiring substrate includes an electrode including Cu or a Cu alloy, and a plated film including an electroless nickel-plated layer formed on the electrode and an electroless gold-plated layer formed on the electroless nickel-plated layer. The electroless nickel-plated layer is formed by co-precipitation of Ni, P, Bi, and S, the electroless nickel-plated layer includes a content of P of 5% by mass or more and less than 10% by mass, a content of Bi of 1 ppm by mass to 1,000 ppm by mass, and a content of S of 1 ppm by mass to 2,000 ppm by mass, and a mass ratio of the content of S to the content of Bi (S/Bi) is more than 1.0.