Provided is a divided-type waveguide tube circuit wherein operation of applying a radio wave leakage preventing material by using a conductive adhesive or performing soldering, brazing or the like iseliminated, and radio wave leakage is suitably prevented by simply fixing a metal cover to a waveguide tube main body by screwing and the like. A radio wave leakage preventing plate (8) which overlapswith an end section of the metal cover (4) is arranged at an end section in a radio wave traveling direction, on an opening surface (3) of the waveguide tube main body (2).