A sealing terminal includes internal connection lines which are connected to heating elements and external connection lines via which power is supplied. A quartz glass body includes a plurality of grooves in its outer surface to retain the internal and external connection lines in place. Conductive foils are used to connect the internal and external lines which are housed in a quartz glass tube so that the ends of the lines project out of the respective ends thereof. A plug is disposed in the lower end of the tube to close the same. Spark generation is prevented while a low electrical resistance sealed terminal which is simple in structure and quick and easy to assemble, results.