A burnishing machine is provided in which both sides of a groove is machined by a single tool without changing the movement direction of a piston.The burnishing machine, includes: a tip configured to press and process a process face; and a pressurizing unit configured to press the tip against the process face, the pressurizing unit including, a piston configured to reciprocate in a direction orthogonal to the tip, a cylinder portion that accommodates the piston such that the piston reciprocates; and a pressurizing mechanism configured to urge the tip to the process face at both timing of pushing the tip against the process face and pulling the tip against the process face by making the piston reciprocate.