Electrostatic chuck and processing apparatus

An electrostatic chuck, comprising:

• a ceramic dielectric substrate including a first major surface and a second major surface, 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;
• a first porous part provided in the ceramic dielectric substrate and being opposite to the gas feed channel;
• and
• a second porous part provided in the base plate and being opposite to the gas feed channel,
• the ceramic dielectric substrate including a first hole part positioned between the first major surface and the first porous part,
• the first porous part including a first porous region including a plurality of pores and a first dense region denser than the first porous region, the first porous region further including at least one first dense part,
• the second porous part including a second porous region including a plurality of pores and a second dense region denser than the second porous region, the second porous region further including at least one second dense part,
• as projected on a plane perpendicular to a first direction from the base plate toward the ceramic dielectric substrate, configuration is such that the first dense part overlaps the first hole part, and at least a part of the second dense part overlaps at least a part of the first dense part, or at least a part of the second dense part contacts at least a part of the first dense part.