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;
• and
• a second porous part provided on the base plate and being opposite to the gas feed channel,
• the second porous part including a second porous region, and a second dense region denser than the second porous region,
• the second porous region including a plurality of second sparse portions, and a second dense portion, the plurality of second sparse portions including a plurality of pores, the second dense portion having a density higher than a density of the second sparse portions, a dimension in a second direction being smaller than a dimension of the second dense region in the second direction,
• each of the plurality of second sparse portions extending in a first direction from the base plate toward the ceramic dielectric substrate,
• the second dense portion being positioned between the plurality of second sparse portions,
• the second sparse portions including a second wall part provided between the plurality of pores,
• a minimum value of a dimension of the second wall part being smaller than a minimum value of the dimension of the second dense portion in the second direction substantially orthogonal to the first direction, and
• at least a part of an edge of an opening on the ceramic dielectric substrate side of the gas feed channel being configured to be a curve.