A simple equipment and process for hydrogen passivation of multicrystalline silicon (mc-Si) solar cells are reported in this work. Hydrogen plasma is generated by means of AC glow discharge in hydrogen atmosphere. Hydrogen passivation is carried out with three different groups of mc-Si solar cells after finishing contacts. The experimental results demonstrate that the photovoltaic performances of the solar cell samples have been improved after hydrogen plasma treatment, with a relative increase in conversion efficiency up to 10.6%.