A microwave cooking appliance includes a door which covers a loading opening of a cooking chamber when closed, and has a profiled trap structure to form with an electrically conductive door flange a lambda quarter-wave trap that frames the loading opening. The trap structure includes a metal choke profile with an open face opposite the door flange, inner and outer metal tongues protruding into the open face laterally on an inside and outside, respectively. The metal tongues are connected electrically to the choke profile and separated from one another by a microwave entry slot covered by a microwave-transparent cover. The choke profile is framed laterally on the outside by a parallel overlap region which protrudes from the door flange and has a cover surface facing the door flange at a distance and made of electrically conductive material and having a same shape as a door flange region it covers.