An electrostatic chuck includes a ceramic dielectric substrate, a base plate, a bonding part, a gas inlet path, a counterbore part, and a ceramic porous part. The bonding part is located between the ceramic dielectric substrate and the base plate. The gas inlet path extends through the ceramic dielectric substrate, the base plate, and the bonding part. The gas inlet path includes a first hole part, a second hole part, and a third hole part. The first hole part is positioned at the ceramic dielectric substrate. The second hole part is positioned at the base plate. The third hole part is positioned at the bonding part. The counterbore part is located in at least one of the first hole part or the second hole part. The ceramic porous part is located in the counterbore part. The ceramic porous part includes an exposed surface exposed in the third hole part.