A door closer, including an output shaft, on which a cam disc is torque-proof disposed, and a pressure roller, wherein a closer spring presses the pressure roller against a running surface of the cam disc by means of a link-plate carriage, wherein the pressure roller is disposed with regard to an axial centre of the output shaft such that the pressure roller, upon opening or closing a swing leaf, which may be coupled to the output shaft, is moved along a path, wherein, based on the circumstance that the path bypasses the axial centre of the output shaft, and based on a configuration of the running surface of the cam disc with a respective opening angle of the swing leaf with different modes of operation of the door closer, respectively a very similar or identical torque is present at the output shaft, • wherein the modes of operation comprise an operation of the door closer with a slide channel, and an operation of the door closer with a standard arm assembly or a scissor arm assembly, and • wherein the door closer with a slide channel operation is mounted on a pull-side and with a standard arm assembly operation is mounted on a push-side, or wherein the door closer with a slide channel operation is mounted on a push-side and with a standard arm assembly operation is mounted on a pull-side, • wherein the cam disc, seen in a first direction (±y) parallel to a longitudinal extension of the output shaft, includes a symmetrical cross-sectional surface, • wherein the bypassing of the path of the pressure roller is configured such that the door closer is adapted for the slide channel operation on a first section of the running surface of the cam disc, and for the standard arm assembly operation on a second section of the running surface of the cam disc, wherein a start of the sections of the running surface of the cam disc consists of a location of the running surface of the cam disc, against which the pressure roller rests, when the swing leaf is closed, • characterized in that the door closer includes an adjusting means for adjusting a distance of the pressure roller with regard to the path thereof in a mounting condition of the door closer, • wherein the adjusting means comprises a mounting bracket, at which the pressure roller is stationarily and freely rotatably disposed, wherein the mounting bracket has a threaded bore, which extends in a second direction (±z) transversely with regard to a longitudinal extension of the output shaft and transversely with regard to a longitudinal extension of the door closer, wherein the link-plate carriage of the door closer has a through opening in such a way, that from an outer side of the link-plate carriage, a screw is screwed into the threaded bore, wherein the mounting bracket is supported in a guided manner in a guide of a link-plate carriage, which is coupled to the closer spring. • wherein the modes of operation comprise an operation of the door closer with a slide channel, and an operation of the door closer with a standard arm assembly or a scissor arm assembly, and • wherein the door closer with a slide channel operation is mounted on a pull-side and with a standard arm assembly operation is mounted on a push-side, or wherein the door closer with a slide channel operation is mounted on a push-side and with a standard arm assembly operation is mounted on a pull-side, • wherein the cam disc, seen in a first direction (±y) parallel to a longitudinal extension of the output shaft, includes a symmetrical cross-sectional surface, • wherein the bypassing of the path of the pressure roller is configured such that the door closer is adapted for the slide channel operation on a first section of the running surface of the cam disc, and for the standard arm assembly operation on a second section of the running surface of the cam disc, wherein a start of the sections of the running surface of the cam disc consists of a location of the running surface of the cam disc, against which the pressure roller rests, when the swing leaf is closed, • characterized in that the door closer includes an adjusting means for adjusting a distance of the pressure roller with regard to the path thereof in a mounting condition of the door closer, • wherein the adjusting means comprises a mounting bracket, at which the pressure roller is stationarily and freely rotatably disposed, wherein the mounting bracket has a threaded bore, which extends in a second direction (±z) transversely with regard to a longitudinal extension of the output shaft and transversely with regard to a longitudinal extension of the door closer, wherein the link-plate carriage of the door closer has a through opening in such a way, that from an outer side of the link-plate carriage, a screw is screwed into the threaded bore, wherein the mounting bracket is supported in a guided manner in a guide of a link-plate carriage, which is coupled to the closer spring.