PURPOSE: To perform image pickup always with good color reproducibility, by taking in a spread light in an objective space through the use of an optical system other than an optical system of pickup lense and automatically adjusting the white balance.

CONSTITUTION: A condenser lens 4 is located at a suitable place other than a pickup lens optical path of a camera and collects external lights. A light from a white diffusion plate 5 passes through a red filter 6 and a blue filter 7 and is incident to a red color detecting element 8 and a blue color detection element 9. The color temperature of light illuminating the objective is operated at a color temperature operation circuit 10 from the ratio of red and blue light detection outputs. The output signal of the circuit 10 is inputted to an automatic white balance adjusting circuit 11 and the gain of R-Y and B-Y color difference signals from an image pickup tube 12 of the camera can automatically be adjusted with this output signal.