To improve the accuracy of bonding between each member and get good electric characteristics in a wave guide antenna comprising a plurality of wave guides made by bonding a plurality of members.

In the top face 7a of a barrier 7, a recess 7c is formed in the center excepting side edges 7b which are wave-guiding sections facing to opening passages 9, and in bonding, the bottom 7d of the recess 7c is separated from a slot array radiation board 5. Since there is no mutual interference between the top face 7a in the recess 7c and the slot radiation board 5 and the fastening strength associated with bonding acts on the side edges 7b in the barrier 7 exclusively, the accuracy of bonding in the barrier 7 can be improved. In the barrier 7, the neighborhood of the side edges 7b facing the opening passages 9 acts as a waveguide exclusively, thereby a good electrical characteristic of bonding faces can be obtained by the improvement of bonding accuracy in the side edges 7b.