A movable contact holder includes a movable contact holder base and a movable contact holder cover. One side of the movable contact holder base is opened to have a plurality of recesses each being formed for holding a contact pair, each contact pair include a bridge contact assembly and a contact spring inserted therein while being isolated from the other pairs. The other side of the movable contact holder base is formed as a bottom wall, and preferably includes openings through which an assembly jig can be inserted from outside the moveable contact holder. Alternatively, jig openings can be formed in lateral side walls of the recesses to allow the assembly jig to be inserted. The movable contact holder cover covers the movable contact holder base and is coupled thereto.