| abstract |
According to the present invention, a ceramic heater (10) is provided with a ceramic member (12), a heater element (14), a connection member (16), and an external conductive member (18). The connection member (16) is a cylindrical metal member that is buried so as to reach from the bottom surface of a hole (12c) in the ceramic member (12) to the heater element (14). In the connection member (16), the diameter (D) is 3.5-5 mm, the corner portion (16b) between a circular surface, which is in contact with the heater element (14), and a cylinder side surface has a curvature radius (R) of 0.3-1.5 mm, and the ratio R/D is 0.09-0.30. The external conductive member (18) is joined to the connection member (16) via a joining layer (20). This ceramic heater (10) makes it possible to increase joining strength in comparison to conventional heaters and reduce the risk of damage to the ceramic member (12). |