An electrostatic chuck device comprising a mounting table having a mounting surface, a focus ring; and a cooling element, wherein the mounting table has a holding portion surrounding the mounting surface, the holding portion has an annular groove portion having a through-hole, the holding portion has inner and outer peripheral surfaces which hold the focus ring and are located on both sides of the groove portion, the holding surface satisfies conditions (i) and (ii), (i) a straight line connecting a first point corresponding to an innermost periphery of the holding surface and a second point corresponding to an outermost periphery of the holding surface has a positive or a negative inclination from the innermost periphery toward the outermost periphery, wherein a difference between a height of the first point and a height of the second point is 0 μm to 10 μm, and (ii) leak areas of the inner peripheral surface and the outer peripheral surface are less than 0.7 mm2.