PURPOSE: To obtain an inexpensive integrated circuit device for processing video signal with an excellent characteristic for signal processing.

CONSTITUTION: A video signal processing integrated circuit device 3 formed on a substrate is provided with a changeover circuit 4, a branch circuit 8 and preamplifier circuits 5-6. A high input impedance input terminal with a sufficiently higher impedance than an output impedance of the changeover circuit 4 receives an output of the changeover circuit 4 and a high frequency component including a highest frequency of the video signal is eliminated and a signal component at a frequency band relating to a synchronizing signal is outputted. The preamplifier circuits 5-7 amplify the video signal outputted from the changeover circuit 4 to provide an output. The branch circuit 8 has a high input impedance to provide a signal to the preamplifier circuits 5-7 without losing the highest frequency component of the video signal and suppresses the frequency of the signal outputted from an output terminal 3p to prevent external interference.