A stereo image pickup apparatus having a plurality of image pickup units, an input selection unit for executing a selection processing of an input signal, a sensor driving signal generation unit for driving the image pickup units, and a camera signal processing unit for executing camera signal processing of output data of the image pickup units. The plural image pickup units simultaneously execute exposure and the sensor driving signal generation unit executes mask control of the driving signal and makes different the output timing of the image pickup data from the image pickup unit. The camera signal processing of the image data outputted from the image pickup units can be carried out by a smaller number of camera signal processing units than the image pickup units.