A Langmuir probe investigation of Ar/H-2/Cp(2)HfMe(2) plasmas is described. The probe measurements were performed for various discharge conditions. The mean electron energy and electron density were measured for various power, gas flows of argon, and hydrgen and precursor concentrations. Addition of the precursor into the discharge resulted in an appreciable decrease in the electron density and art increase in the mean electron energy. Whereas a transition from the alpha-mode to the gamma-mode has beert observed with power rise in the Ar/H-2 plasmas without precursor in the presence of the precursor the plasma alpha-mode remained unchanged in the power range investigated.