Gas sensor

摘要

A gas sensor includes a sensor element which contains a solid electrolyte, and has a cylindrical shape that is closed at one end and is opened at the other end; and a ceramic heater which is formed into a rod shape, and is inserted and disposed in the sensor element. A peripheral edge of a lower end of the ceramic heater contacts an inner face of a bottom portion of the sensor element. The peripheral edge of the lower end of the ceramic heater has a shape that fits the inner face of the bottom portion of the sensor element at a portion of contact between the sensor element and the ceramic heater.