PURPOSE: To exactly detect the phase shift of a color demodulation axis even when the level of an input signal is low by calculating the phase shift between a color burst and the color demodulating axis based on the output values of two average value calculation circuits and outputting the phase shift to a color separator.

CONSTITUTION: An average value calculation circuit 12 inputs a sampling clock (k) from an input terminal 15, samples a value in the color burst block of a color difference signal e(R-Y) constant times, calculates the average of the sample values for each line and outputs an average value l(R-Y) to a color burst phase shift calculation circuit 14. An average value calculation circuit 13 similarly outputs an average value m(B-Y) to the color burst phase shift calculation circuit 14. Based on the average values l(R-Y) and m(B-Y), the phase shift calculation circuit 14 calculates the phase shift between the color burst and the color demodulating axis and outputs it to a color separator 5. Thus, even when the amplitude of the color burst of the input signal is low, the phase shift of the demodulating axis can be accurately detected.