| 摘要 |
This ceramic heater is provided with: a ceramic structural body; a heat generating resistor embedded in the ceramic structural body; and a power supply line, which is embedded in the ceramic structural body, and which has one end thereof connected to the heat generating resistor. The power supply line is formed of a metal, and in the power supply line, the diameter of metal grains in a center portion is larger than the diameter of metal grains in an outer circumferential portion. Consequently, even if a crack generated in the outer circumferential portion of the power supply line extends close to the center portion through grain boundaries in the outer circumferential portion, progress of the crack into the center portion can be suppressed. |
