PURPOSE: To provide an EDTV decoder in which an excellent image without a sense of incongruity is displayed when an EDTV decoded signal is viewed by a monitor whose aspect ratio is 16:9 or viewed by a monitor whose aspect ratio is 4:3.

CONSTITUTION: A disturbance reduction countermeasure decoding VT/VH separate circuit 3 separate a VT signal and a VH signal. A noninterlace scanning VT synthesis circuit 4 synthesizes a luminance signal and a VT signal of a major image. An interlace scanning VH synthesis circuit 5 synthesizes a luminance signal and a VH signal of a major part to convert scanning lines. A color demodulation circuit 6 demodulates a color signal of the major part to obtain I, Q signals. A horizontal compression circuit 11 compresses outputs of the scanning line conversion VH synthesis circuit 5 and the scanning line conversion circuit 7 toward left and right ends to convert a decode signal whose aspect ratio is 16:9 into a signal whose aspect ratio is 4:3 and provides an output.