A pedestal level of each of the R-Y and B-Y signals (color-difference signals) in a horizontal synchronization time T1 of a horizontal synchronizing signal is detected, and a pedestal level adjustment value for adjustment of the pedestal level of each of the R-Y and B-Y signals is determined based on the pedestal level determined in such a manner that a difference in pedestal level of each of the R-Y and B-Y signals between in the horizontal synchronization time T1 and in a horizontal scanning time T2 of the horizontal synchronizing signal is lessen.The pedestal level adjustment value determined is stored and video amplification-chroma circuit 130 adjusts the pedestal level of each of the R-Y signal and the B-Y signal in the horizontal synchronization time T1 of the horizontal synchronizing signal by an amount of adjustment value stored in.