The domestic appliance (1) has a treatment chamber (2) that is operatively connected with the antenna (3) through a connecting unit (5). A coupling unit (4) is provided in the treatment chamber and is provided an arbitrarily shaped coupling element. A transmitting and/or receiving unit (11) is arranged in the coupling unit used for electromagnetic waves. The matching elements of different areas are arranged in the coupling unit. An insulator (7) is arranged between the coupling unit and the antenna.
