PURPOSE: To make a circuit stable, to reduce the scale and to solve various problems relating to aspect ratio conversion in a image pickup device able to convert aspect ratio.

CONSTITUTION: The stability of the device circuit and the reduction in the scale are attained by the arrangement of a wide screen compatible image pickup element 2, an A/D converter 4 applying A/D-conversion to an analogically processed image pickup signal, a gamma processing circuit 5 applying basic processing of the image pickup device to an output signal of the A/D converter 4, an enhancement processing circuit 6, and a matrix processing circuit 7 being components of a digital process section, and an aspect ratio conversion circuit 9 applying aspect ratio conversion in this order. Furthermore, each setting value is switched in response to the switching of the aspect ratio by a microcomputer 8, then various problems caused in processing such as enhancement processing, and blanking processing and a problem in mixture with the image pickup device compatible with a normal size screen are solved.