Electrostatic chuck

An electrostatic chuck comprising:

• a ceramic dielectric substrate having a first major surface for mounting a suction target and a second major surface on opposite side from the first major surface;
• a base plate supporting the ceramic dielectric substrate and including a gas feed channel;
• and
• a first porous part provided at a position between the base plate and the first major surface of the ceramic dielectric substrate, the position being opposed to the gas feed channel,
• the ceramic dielectric substrate including a first hole part located between the first major surface and the first porous part,
• the first porous part including:
• a porous section including a plurality of pores;
• and
• a first compact section being more compact than the porous section, and
• the porous section including a plurality of sparse portions including a plurality of pores including a first pore and a second pore, and a dense portion having a higher density than the sparse portion,
• each of the plurality of sparse portions extending in a first direction,
• the dense portion is located between the plurality of sparse portions, and
• in the second direction, dimension of the plurality of pores provided in each of the plurality of sparse portions is smaller than dimension of the dense portion.