PURPOSE: To improve the picture quality of broadcast waves of the inferior signal quality.

CONSTITUTION: A picture quality improving device 20 including a high frequency signal processing part and a base band signal processing part is provided in an outdoor booster set near an antenna or a desk booster set near a TV receiver. The high frequency signal inputted through the antenna is transmitted through a band limiting circuit 22, a high frequency signal amplifier circuit 23, and a distortion component eliminating circuit 24 respectively. Thus a signal whose S/N value and amplitude are improved is supplied to a tuner part of a video reproducer 26. The base band signal selected by the reproducer 26 is once outputted to the outside and then applied to a base band signal processing circuit 29 to eliminate the ghost signal component, etc., for improvement of the picture quality. Then the base band signal is applied again to the reproducer 26. Thus it is possible to eliminate the proper reception fault that is caused by the installing environment of the reproducer 26.