Abstract: A bone resection apparatus may comprise a roughly planar blade body that has a tip saw blade and that carries out cutting of bone with which the tip saw blade makes contact as a result of high-speed oscillation; and a guide plate which has a roughly planar tip guide portion, which is located at a top side of the blade body, and which is connected in such fashion as to permit sliding in a front-and-back direction relative to the blade body, the guide plate being capable of sliding between a protruding guide state in which the tip guide portion is made to protrude toward the tip to a point beyond the tip saw blade of the blade body to cover the tip saw blade and to guide a location in a thickness direction at which cutting by the tip saw blade occurs, and a retracted guide state in which the tip guide portion is retracted to a point behind the tip saw blade.