The high target power density (up to similar to 1000 W cm(-2)) of a magnetron sputtering process was studied by means of optical emission spectroscopy and Langmuir probe characteristics. The goal of this research was to estimate the composition (neutrals and ions) and parameters of the plasma (temperature T-e and density n(e) of electrons) at different technological parameters. Copper targets with a diameter of 50 and 100 mm were sputtered. The argon pressure was changed from 0 (final pressure equal to 1 x 10(-5) torr) to 5 x 10(-3) torr. This corresponded to self-sustained (at the final Vacuum pressure) and standard argon sputtering modes, respectively. The dominant role of copper ions was observed (404.3(+) nm ion line intensity in relation to 402.3* and 406.3* excited neutrals line intensities) during both the self-sustained and argon modes of high target power density. The line intensity of copper ions near the etched target surface (cathode voltage fall) increased substantially when the target current increased. The substrate current density (at a distance between target and substrate equal to 9 cm) increased significantly with the decrease of the parallel component of the magnetic field intensity (at constant target current). At this distance, a sputtering rate of similar to 5 mum min(-1) was achieved for the Cu target of 50 mm in diameter.