A treatment apparatus for producing a cut in a transparent material (7, 8), which comprises - a laser device which is configured to generate a cut within the transparent material (7, 8) by means of optical radiation and which laser device comprises - optics which focus the optical radiation along an optical axis into a focus situated in the material and which have in the material (7, 8) an image field in which the focus lies and which has an image field size, and - a focus position adjustment device for moving a position of the focus transverse to the optical axis and along the optical axis, - a control device which is connected to the laser device and controls the laser device such that the focus position adjustment device moves the position of the focus of the optical radiation in the material (7, 8) along a path (10.2), wherein the control device controls the laser device such that, perpendicular to the optical axis, comprises the cut (9.2), wherein the control device prescribes for the focus position adjustment device a lateral movement of the positon of the focus transvers to the optical axis which is located in a sectional plane along the curve (K.2) and prescribes along the optical axis during the lateral movement a multiple axially oscillating axial adjustment of the position of the focus between an upper axial focus position and a lower axial focus position, wherein optionally the upper axial and the lower axial focus position vary along the curve (K.2) and/or optionally a distance between the upper axial and the lower axial focus position are not constant along the curve (K.2), characterized in that the control device synchronizes the lateral focus adjustment to the axial focus adjustment and prescribes at least in sections an additional lateral focus adjustment synchronous to the axial focus adjustment such that the cut (9.2) is at least in sections inclined against the optical axis, wherein the additional lateral focus adjustment is small compared to the extent of the curve (K.2). - a laser device which is configured to generate a cut within the transparent material (7, 8) by means of optical radiation and which laser device comprises - optics which focus the optical radiation along an optical axis into a focus situated in the material and which have in the material (7, 8) an image field in which the focus lies and which has an image field size, and - a focus position adjustment device for moving a position of the focus transverse to the optical axis and along the optical axis, - optics which focus the optical radiation along an optical axis into a focus situated in the material and which have in the material (7, 8) an image field in which the focus lies and which has an image field size, and - a focus position adjustment device for moving a position of the focus transverse to the optical axis and along the optical axis, - a control device which is connected to the laser device and controls the laser device such that the focus position adjustment device moves the position of the focus of the optical radiation in the material (7, 8) along a path (10.2), wherein the control device controls the laser device such that, perpendicular to the optical axis, comprises the cut (9.2), wherein the control device prescribes for the focus position adjustment device a lateral movement of the positon of the focus transvers to the optical axis which is located in a sectional plane along the curve (K.2) and prescribes along the optical axis during the lateral movement a multiple axially oscillating axial adjustment of the position of the focus between an upper axial focus position and a lower axial focus position, wherein optionally the upper axial and the lower axial focus position vary along the curve (K.2) and/or optionally a distance between the upper axial and the lower axial focus position are not constant along the curve (K.2), characterized in that the control device synchronizes the lateral focus adjustment to the axial focus adjustment and prescribes at least in sections an additional lateral focus adjustment synchronous to the axial focus adjustment such that the cut (9.2) is at least in sections inclined against the optical axis, wherein the additional lateral focus adjustment is small compared to the extent of the curve (K.2).