Abstract: A honeycomb structure body has a honeycomb base body and a pair of electrodes composed of conductive ceramic layers and intermediate layers. The honeycomb base body made of porous ceramics containing SiC is comprised of a cell formation part and an outer peripheral part. The outer peripheral part covers the cell formation part. Each electrode is comprised of a conductive ceramic layer and an intermediate layer. The conductive ceramic layers containing SiC, Si and C are formed at two opposite positions on the outer peripheral part observed from a diameter direction. The intermediate layers containing SiC, Si and C are formed in the outer peripheral part at the parts which face the conductive ceramic layers. The honeycomb structure body satisfies a relationship of 0.5?t/T?1, where “t” indicates the thickness of the intermediate layer and “T” indicates the thickness of the outer peripheral part.

Abstract: A far infra-red heater comprises a resistance heating element composed of an insulating and heat resistance structural material and 5 to 60% by weight of Si or FeSi as a conductive material dispersed in the structural material. In the far infra-red radiating heater, a ceramic resistance heating element per se efficiently radiates light having a wave length falling within the far infra-red region, the heater has high thermal efficiency and sufficient mechanical strength and can be used at a temperature of up to about 600.degree. C.

Abstract: A small ignition device comprising a string-like silicon carbide heating element extending between and joining in electrical connection respective silicon carbide rod-like terminals. The heating element is joined to the terminals by an electrically conductive silicon joint. The string-like element has all cross-sectional dimensions between 0.05 mm and 2 mm and has a resistivity of between 0.01.OMEGA..multidot.cm and 10.OMEGA..multidot.cm whereby said heating element is heated to between about 1000.degree. C. and 1300.degree. C. in about 1 to 4 seconds after an electric current is connected thereto.