To provide a ceramic heater capable of accurately maintaining the homogeneity of the temperature distribution on a semiconductor wafer mount face even when the temperature of the mount face is changed during a process.

This ceramic heater is provided with a disk-shaped ceramic insulating substrate having a semiconductor wafer mount face and a heating resistor nearly concentrically arranged with resistance wires 11 in the insulating substrate, and the heating resistor is made of a resistor having a positive temperature coefficient. A plurality of resistance wires 11 arranged concentrically in the radial direction are connected in parallel by feeder lines 16-19 extended radially on at least part of the heating resistor to form a parallel circuit pattern, the temperature change of this portion is automatically corrected by the change of the heating quantity due to the resistance change of the resistor under a constant voltage, and the temperature distribution of the wafer mount face is accurately kept homogeneous.