A first inner housing and a second inner housing are combined to form a combined inner housing, in which the first inner housing having a plurality of mutually independent insertion holes is formed of a first dielectric or an electric conductor, and the second inner housing having a plurality of mutually independent terminal-housing chambers is formed of a second dielectric. Terminals of a twisted-pair cable are inserted and housed one-to-one in the terminal-housing chambers of the combined inner housing. The twist-released sections of sheathed cables of the twisted-pair cable are inserted and housed one-to-one in the insertion holes of the combined inner housing. The combined inner housing is covered with a shield member, and the combined inner housing and the shield member are housed in an outer housing.