The invention relates to a machine tool with an adjustable cutting plate. The rotating machine tool substantially comprises a base member (12) with a rotating axis (10), at least one pocket (24) formed in the base member (12) and at least one blade support (20) holding a cutting plate (18). Two side surfaces (30, 32) of the blade support (20) sit against a side support surface (34, 36), respectively, said blade support side surfaces making an angle between them, and the base (38) of the blade support sits against a base support surface (40) of the pocket (24), the blade support being clamped in the pocket removably by way of a clamp element (28). The cutting plate (18) protrudes over the blade support (20) with an effective blade (23) and over the base member (12) outward. In order to enable a fine-adjustment of tangential cutting plates in the base member, it is proposed that the base support surface (40) form a wedge surface that includes an acute angle together with a shift axis (56), said wedge surface disposed at an adjusting member (58) that can shift relative to the base member (12) along said shift axis (56), the base (38) of said blade support (20), in the shape of a complementary wedge, abutting against said wedge surface. Also, the two side support surfaces (34, 36) form guide surfaces for the blade support (20) that are directed substantially perpendicular relative to the shift axis (56) of the adjusting member (58) when said blade support (20) makes a shifting motion by way of a shifting of the adjusting member (58).