There is provided a polishing tool which enables a polishing surface thereof to be in surface contact with a to-be-polished surface over a wide area of the polishing surface when polishing a corner portion, and which can reduce an impact of a polishing member caused when the polishing member hits against a member around the polishing member. A generally triangular polishing member having apex angles of 60 degrees is connected, through the intermediary of an oscillation transmitting member made of a plate-like spring member, to an oscillating shaft oscillated by a motor. The oscillation transmitting member has a triangular base having at the center thereof a fixing hole by which the triangular base is fitted and fixed to the oscillating shaft, and triangular polishing member holding portions each extending from each side of the triangular base. The polishing member has three polishing pieces each composed of a pad held by the polishing member holding portion and a polishing sheet laminated to the pad. The edge of the polishing piece extends outwardly beyond the edge of the polishing member holding portion.