A finishing tool, includes: a housing having a cylindrical holder chamber that opens toward a distal end and located along a central axis; a slide sleeve disposed coaxially with the central axis in the holder chamber and rotates only in a first direction; a drive sleeve disposed coaxially with the central axis in the holder chamber and rotates only in the first direction; a tool chip having a spherical surface at a distal end; and a chip holder penetrating the slide sleeve and the drive sleeve, reciprocable between a forward end and a rearward end, capable of mounting the tool chip at a distal end, axially slidable relative to the slide sleeve, and rotates in the first direction as the chip holder moves forward relative to the drive sleeve.