Electrostatic chuck

An electrostatic chuck device, comprising:

• an electrostatic chuck plate which has
• a dielectric substrate having a placement surface on which a wafer is placed and
• electrodes which are positioned in the dielectric substrate;
• a focus ring which is installed on an outer peripheral portion of the electrostatic chuck plate and surrounding the placement surface;
• and
• a power connection portion, wherein the power connection portion includes a current regulator and power wires which connect the electrodes and a power supply,
• the electrodes of the electrostatic chuck plate have a first electrode which is positioned in a region overlapping the placement surface in plan view and a second electrode which is positioned in a region overlapping the focus ring in plan view, and
• the power wires of the power connection portion include a power wire which electrically connects the first electrode and the second electrode via the current regulator,
• wherein the current regulator is a constant current circuit in which a first transistor, a resistor, and a second transistor are connected in this order,
• a drain of the first transistor is disposed on an input terminal side,
• a source of the first transistor is connected to an IN side terminal of the resistor and a gate of the second transistor,
• a gate of the first transistor is connected to an OUT side terminal of the resistor and a source of the second transistor,
• a drain of the second transistor is disposed on an output side, and
• the gate of the second transistor is connected to the IN side terminal of the resistor and the source of the first transistor.