A connector includes two insulators which hold contacts connected to lead wires and are arranged on two surfaces of a ceramic element, a spring component which includes two cantilever-shaped spring pieces and has a flexed portion at a middle portion of each spring piece, and a cylindrical sleeve. The two spring pieces are located over two outer surfaces of the two insulators, and are elastically deformed toward the two insulators by the sleeve hanging over the two spring pieces. The two insulators pushed by the flexed portions of the two elastically deformed spring pieces hold the ceramic element from two sides to push the contacts against the terminal electrodes.