| 摘要 |
A ceramic heater (1) has a structure in which a resistance heating element (12) mainly composed of a metal having a high melting point is embedded in a ceramic substrate (11). The average grain size dH for grains of said resistance heating element (12) is caused to be in the range 0.3 to 1.2 mu m; and grains of said resistance heating element (12) are such that, the difference between a grain size d90%, (i.e. the grain size which 90% of the grains are smaller than), and a grain size d10%, (i.e. the grain size which 10% of the grains are smaller than), i.e. a difference d90% - d10%, is not greater than 1.5 mu m. <IMAGE> |
