An electrostatic chuck device that adsorbs a plate-like specimen with an electrostatic adsorption electrode and cools the plate-like specimen, including an electrostatic chuck portion, a forming material of which is a ceramic sintered body, and that has one main surface that is a placement surface on which the plate-like specimen is placed, in which a plurality of protrusions supporting the plate-like specimen are provided on the placement surface, the protrusion has a top surface that is in contact with the plate-like specimen and supports the plate-like specimen, and has a cross-sectional area that gradually increases vertically downward from a height position of the top surface, and a cross-sectional area at a distance 0.6 μm vertically downward from a lower end of the top surface of the protrusion is 110% or less of a cross-sectional area of a lower end of the top surface.