A coating apparatus which combines two material modification techniques, sputter coating and plasma immersion ion implantation, is described. The plasma is generated by an electron cyclotron resonance microwave plasma source. In the upper part of the vacuum chamber, the plasma is confined in a magnetic field by means of a solenoid. In the lower part, a magnetron sputter cathode is mounted which is used for depositing thin films on the sample. The sample is clamped onto a water-cooled sample holder which can be moved in vertical direction. It is connected to a semiconductor-based high voltage pulse generator which provides negative voltage pulses. In this apparatus, a substrate can be pre-implanted by plasma immersion ion implantation, then it can be coated by sputtering. Finally, the sputtered film can be modified by another ion implantation step.