To provide a purifying method for a silicon product with which a metal contamination material is almost completely removed.

After an oxidized film is removed by immersing the silicon product in hydrofluoric acid and a contaminated top layer is dissolved and removed by immersing the silicon product in a mixed liquid of hydrofluoric acid and nitric acid, the adsorbed metal contamination material on a surface of the silicon product is liberated by immersing the silicon product in a mixed liquid of hydrofluoric acid, nitric acid and hydrochloric acid and afterwards, the silicon product is rinsed in pure water and naturally dried.