PURPOSE: To obtain a matched gain even when difference is present between the characteristics of respective automatic gain control(AGC) circuits by controlling the gain of a second AGC circuit based on the objective gain characteristic of a first AGC circuit and the detected result of the gain of the second AGC circuit.

CONSTITUTION: The gains of AGC circuits 5R, 5G and 5B are controlled by gain control signals S22R, S22G and S22B respectively inputted from a control circuit 24, the levels of image pickup signals S2R, S2G and S2B are controlled by the set gain, and image pickup signals S23R, S23G and S23B are outputted. Then, a memory 25 stores the target gain characteristic of the AGC circuit 5G. Namely, the control circuit 24 executes a processing to match the gains of the respective AGC circuits 5R, 5G and 5B by correcting the gains of the AGC circuits 5R and 5B while using the gain characteristic of the memory 25 as a reference.