To provide an electrolytic method with bubbles generated in an electrolyte decreased in electrolysis such as electroplating and capable of performing good electrolysis, an electrolyte and a method for producing a semiconductor device using the electroplating method by the electrolyte.

An electrolyte admixed with 0.01-5% nonionic surfactant as an antifoaming agent is used to conduct such electrolysis as electroplating. An acetylenediol surfactant, an ethylene glycol surfactant, a polyethylene glycol surfactant, or the like, are used as the nonionic surfactant. When copper is electroplated, an electrolyte prepared by adding a nonionic surfactant to an aq. copper sulfate soln. as an antifoaming agent is used.