A heater includes a base body, terminal and joining layer. The base body is made of ceramic. The joining layer contains metal as a principal ingredient and is located between the base body and the terminal. The base body includes a first surface and second surface. The first surface faces an outer side of the base body and includes at least one of a region which is superimposed on the terminal and a region which is located on a periphery of the terminal. The second surface intersects with the first surface and is located on the side closer to an internal portion of the base body on the side away from the first surface. The joining layer extends from the terminal and first surface up to the second surface.