Ceramic heater producing method

A method of producing a ceramic heater, comprising the steps of:

• molding a ceramic heater core in a rod shape having first and second cavities elongated axially thereof, and heater front and rear ends, wherein the first cavity opens at the rear end of the heater core, and the second cavity opens at the front end of the heater core, the heater core further having a pair of flattened portions near the rear end of the heater core;
• printing a conductive heater pattern on the outer peripheral surface of the heater core while rotating the heater core about the first and second cavities, the heater pattern including end portions formed on the respective flattened portions;
• printing a protective layer to cover the heater pattern except for the end portions while rotating the heater core about the first and second cavities;
• and
• burning the heater core along with the printed protective layer.