PURPOSE: To facilitate the mount of the device onto an existing television receiver while offering the use of an adaptor by detecting a frequency band when a disturbing wave detected for a blanking period of a received television receiver reaches a prescribed level or over and inserting a block filter so as to eliminate the wave.

CONSTITUTION: A disturbing wave detection section 2 samples part of a blanking period of a received television signal branched from a disturbing wave elimination section 1 to extract only the disturbing wave and integrates the disturbing wave for a prescribed time and sends a control signal to a control section 3 when the level exceeds a prescribed level. In this case, the disturbing wave elimination section 1 consists of block filters NF1 - NF7 eliminating specified seven disturbing waves and analog switches SW1 - SW7 and the block filter NF is inserted by a command of the control section 3. The control section 3 applies insertion control of the block filters NF1 - NF7 in the elimination section and the control of the detection section 3. Thus, the constitution is simplified and the device is manufactured inexpensively and the device is used as an adaptor for a general home use television receiver.