Ceramic heater, glow plug, and ceramic heater manufacturing method

摘要

A ceramic heater which includes: a cylindrical substrate including an insulator; a resistor provided in one end side of the substrate; a pair of lead parts provided in the substrate, connected to the resistor and extending to an opposite end side of the substrate; and a pair of electrode parts exposed to a surface at an opposite end side of the substrate and connected respectively to the lead parts. Both lead parts are made of the same material as both electrode parts. An axial cross-sectional area of the electrode part is equal to or larger than a cross-sectional area of the lead part in a direction perpendicular to an axis of the ceramic heater.