To allow the grinding of a back portion and a cutter portion of a round cutter at the same time by giving oscillating operation to an operation lever mounted on a base when grinding the round cutter in use for a power bush cutter.

This round cutter grinding machine comprises a round cutter holder 3, a grinder 4 and a operation lever 5 arranged on the base 2, the operation lever 5 having an engagement portion formed deviating from an axial center of a turning shaft 6. Upon intermittently turning the round cutter holder 3 with the movement of the engagement portion due to the turning of the turning shaft 6, the grinder 4 is fed to the side of the cutter holder 3 or the cutter holder 3 is pulled to the side of the grinder 4.