Production of hydrocarbon radicals is controlled by using a whistler wave discharge in range of radio frequency in a low pressure region (approximately 0.1 Pa). Plasma density of 10(10)-10(13) cm-3, electron temperature of 2-20 eV is obtained for the discharge of the admixture of Ar and small content of source gases (CH4, C2H2, CO). Spectroscopic measurement indicates that densities of CH and H radicals and the deposition rate of amorphous carbon:H film increase with electron density, electron temperature, and source gas pressure. The etching effect of H atoms influences on the deposition rate and a high deposition rate (90-mu-m/h for CO/Ar discharge) is obtained even in a low neutral pressure discharge.