A movement unit of a machine tool • having a supporting structure movable in a feed direction for mounting a functional unit (5, 6) of the machine tool, • having a guide means for the supporting structure, which guide means comprises two longitudinal guides (14, 15) extending in the feed direction and arranged offset relative to one another in a guide transverse direction transverse to the feed direction, on which longitudinal guides (14, 15) a guide unit (12, 13) of the guide means may in each case be moved in the feed direction and is mounted without play in the guide transverse direction, and • having a bearing means, by means of which the supporting structure is mounted on one of the guide units (12, 13) without play in the feed direction and floatingly in the guide transverse direction, the bearing means comprising a supporting structure-side bearing part associated with the supporting structure and a guide-side bearing part associated with the guide unit, of which one is constructed as a bearing receptacle extending in the guide transverse direction with a receptacle wall and the other is constructed as a bearing projection engaging in the bearing receptacle, wherein the bearing projection and the receptacle wall of the bearing receptacle are mounted against one another without play in the feed direction and the bearing receptacle is oversized in the guide transverse direction relative to the bearing projection engaging in the bearing receptacle and wherein the bearing projection is connected with the supporting structure or with the guide unit so as to be rotatable about an axis extending perpendicular to the plane defined by the feed direction and the guide transverse direction, characterised in that the bearing projection connected with the supporting structure or with the guide unit so as to be rotatable about the axis and the receptacle wall of the bearing receptacle are mounted without play against one another in the feed direction, and the bearing projection connected with the supporting structure or with the guide unit so as to be rotatable about the axis and the receptacle wall of the bearing receptacle are pretensioned relative to one another in the feed direction and, through the effect of this pretensioning, can be readjusted relative to one another in the feed direction. • having a supporting structure movable in a feed direction for mounting a functional unit (5, 6) of the machine tool, • having a guide means for the supporting structure, which guide means comprises two longitudinal guides (14, 15) extending in the feed direction and arranged offset relative to one another in a guide transverse direction transverse to the feed direction, on which longitudinal guides (14, 15) a guide unit (12, 13) of the guide means may in each case be moved in the feed direction and is mounted without play in the guide transverse direction, and • having a bearing means, by means of which the supporting structure is mounted on one of the guide units (12, 13) without play in the feed direction and floatingly in the guide transverse direction, the bearing means comprising a supporting structure-side bearing part associated with the supporting structure and a guide-side bearing part associated with the guide unit, of which one is constructed as a bearing receptacle extending in the guide transverse direction with a receptacle wall and the other is constructed as a bearing projection engaging in the bearing receptacle, wherein the bearing projection and the receptacle wall of the bearing receptacle are mounted against one another without play in the feed direction and the bearing receptacle is oversized in the guide transverse direction relative to the bearing projection engaging in the bearing receptacle and wherein the bearing projection is connected with the supporting structure or with the guide unit so as to be rotatable about an axis extending perpendicular to the plane defined by the feed direction and the guide transverse direction,