Production of high plasmas in anchor-cell is necessary for MHD stabilization on the tandem mirror GAMMA10. Plasma heating in anchor-cell has been carried out by ICRF system (RF1) with both east and west Type-III antennas installed in the central-cell. By using an additional ICRF system (RF3) with a bar-type antenna installed in the east anchor-cell, more effective anchor heating has been confirmed. East Type-III and the bar-type antennas are driven with the same frequency and phase difference between two antennas can be controlled in the experiment. Plasma parameters depend on the phase difference between both antennas. Increase of the line density and the soft X-ray signal are observed in the opposite phase. Stable plasma production with only east RF1 and east RF3 are also confirmed.