Ceramic heater

A ceramic heater, comprising:

• a plate including:
• a first principal surface configured to support a wafer;
• and
• a second principal surface positioned across a gap from the first principal surface in a thickness direction of the plate;
• a first heater layer which is built in the plate, and which is formed from a resistance heating element configured to generate heat through energization;
• a plurality of first power feeding terminals which are built in the plate so as to be arranged in a central portion of the plate when viewed in the thickness direction, and which are connected to the first heater layer;
• a second heater layer having a ring shape which is built in the plate so as to be arranged on an outer side of the first heater layer when viewed in the thickness direction, and which is formed from a resistance heating element configured to generate heat through energization;
• a plurality of second power feeding terminals which are built in the plate so as to be arranged in the central portion of the plate when viewed in the thickness direction, and which are configured to feed power to the second heater layer;
• and
• a plurality of jumper layers which are built in the plate so as to be arranged on the second principal surface side with respect to the first heater layer in the thickness direction and arranged on an inner side of the second heater layer when viewed in the thickness direction,
• wherein each of the plurality of jumper layers is connected to a corresponding one of the plurality of second power feeding terminals, and is connected to the second heater layer through intermediation of a corresponding one of a plurality of connecting portions provided to the second heater layer,
• wherein the plurality of jumper layers each have at least one slit which divides the jumper layer into a plurality of regions, the plurality of regions including at least:
• a first region being an innermost region including a first end portion to which a corresponding one of the second power feeding terminals is connected;
• and a second region being an outermost region including a second end portion to which a corresponding one of the connecting portions is connected, when viewed in the thickness direction, the plurality of regions being continuous so that the first region extends in a positive circumferential direction and the region other than the first region extends in an opposite circumferential direction to a direction in which the region being adjacent on an inner side extends, and
• wherein widths of the plurality of regions are larger than a width of the resistance heating element which forms the second heater layer.