Electrostatic chuck and processing apparatus

An electrostatic chuck, comprising:

• a ceramic dielectric substrate including a first major surface, a second major surface, and at least one groove, a suction target being placed on the first major surface, the second major surface being opposite to the first major surface;
• a base plate supporting the ceramic dielectric substrate and including a gas feed channel;
• and
• a first porous part provided between the groove and the gas feed channel,
• the ceramic dielectric substrate including a plurality of holes communicating with the groove and the gas feed channel and piercing the ceramic dielectric substrate in a first direction from the base plate toward the ceramic dielectric substrate,
• the first porous part including at least one porous region including a plurality of pores, and at least one dense region denser than the porous region, the porous region further including at least one dense part
• as projected on a plane perpendicular to the first direction, at least one of the plurality of holes provided in the ceramic dielectric substrate being configured to overlap at least one of the dense part.