Disclosed herein is a method for surface treatment which comprises subjecting an object for surface treatment to an atmospheric pressure plasma while rolling or floating said object in an insulating vessel fed with a prescribed gas and provided on the outside thereof or on both the outside and inside thereof with electrodes for voltage application and grounding, said atmospheric pressure plasma occurring upon application of a voltage to said electrodes. This method permits simple, certain, and uniform surface treatment of any objects in the form of lump or sphere. The surface treatment by the atmospheric pressure plasma does not need the apparatus to be evacuated. Therefore, it can be carried out in a simple apparatus without causing the object for surface treatment to release volatile matters.Disclosed also herein is a method for the surface treatment of vulcanized rubber with an atmospheric pressure plasma in the presence of an oxygen-containing gas and halogen containing gases. This method is simple and permits the surface treatment of vulcanized rubber in a clean environment. The surface treatment by this method provides the vulcanized rubber with a surface having better adhesion properties than the surface treatment with a low-pressure glow plasma. Moreover, the surface treatment is limited only to a very thin surface layer, with the vulcanized rubber itself remaining intact.