Abstract: An internal grinding machine for grinding the inner surface of a work comprises a traverser table (11) mounted on a bed (10) for sliding movement in the longitudinal direction of the bed, a grinding head (15) mounted on the table for free position adjustment in the longitudinal direction, and a grinder shaft spindle (16) fixed to the upper surface of the grinding head (15) and provided on the front end surface thereof with a grinder shaft which carries at its end a grinder (19), the traverser table being adapted to slide so as to bring the grinder to a predetermined position with respect to the work, wherein the grinding head being arranged such that its rear end can swing to the left and right about the center (17) of the front end thereof, the rear end of the grinding head being connected to an eccentric cam mechanism (21) which in turn is connected to a driving portion (22), so that the grinding head is swung by a predetermined angle in accordance with the amount of eccentricity of the eccentric cam mechan