Abstract: The present invention relates to a clamping device for joining two waveguides used for propagating microwaves. The waveguides are of the type comprising hollow microwave propagation channels having at their meeting ends connection flanges in abutting relationship, the flanges being provided with aligned openings. The clamping device comprises a top wall and a pair of generally parallel side walls depending from the top wall. A metallic pin is mounted to one of the side walls and projects toward the other side wall which is provided with a cut-out portion facing the pin. In use, the pin is inserted through a pair of aligned openings in the flanges and the clamping device is pressed toward the flanges to turn about the axis of the pin until the flanges are deeply received between the side walls.