PURPOSE: To obtain a signal processing circuit of each channel, which can solve troubles relating to a temperature characteristic, etc., by arraying symmetrically the even-number of signal processing circuits so as to make them integrated and causing the symmetry to form a difference signal between channels so as to input it.

CONSTITUTION: Signals R, G and B inputted from input terminals 1, 2 and 3 are supplied to processing circuits 4, 5, 6 and 7. The strain of the processing circuits 4 and 5 and that of the processing circuits 6 and 7 are made integrated on the same chip, and action characteristics of the circuits 4 and 5 become coincident and the same coincidence can be obtained in the circuits 6 and 7. When signals processed by such processing circuits 4, 5, 6 and 7 are applied to subtractors 8 and 10 and an adder 9, a luminance signal of an NTSC system can be obtained from the adder 9, while from the subtractors 8 and 10 red and blue color difference signals can be obtained. Since these color difference signals are formed in the processing circuits of the same action characteristic, the white balance can be secured.