An image display device, having a casing in which a television device and a video device are enclosed, includes a main circuit board having a first area for installing electronic parts of a power supply circuit and a second area for installing remaining electronic parts for TV and video device. Since the electronic parts of the power supply circuit are arranged within a separated area formed on the main circuit board, the electronic parts for the TV device and the electronic parts for the video device can be installed with high density and with no substantial interference with each other.