Electrostatic chuck and substrate fixing device

An electrostatic chuck comprising:

• a heating part;
• a substrate on the heating part,
• the substrate including
• a first surface onto which an object is to be attracted and held, and a second surface opposite from the first surface and contacting the heating part;
• and
• a first hole and a second hole aligned in a thickness direction of the substrate in communication with each other, the second hole being closer to the heating part than is the first hole, and open at the second surface of the substrate, the second hole being larger than the first hole when viewed in the thickness direction of the substrate;
• a temperature sensor at a bottom of the first hole;
• and
• a metal material in the second hole with a space between the temperature sensor and the metal material,
• wherein there is a gap between a side surface of the metal material and an inner wall surface of the second hole.