0 1 wt or less and a relative density of 98 or more the variation in the thickness of the dielectric layer was 52 u03bcm the electrostatic electrode paste was printed on the lower surface of an alumina sintered body and the heater electrode paste was printed on the upper surface of another alumina sintered body an alumina granulated powder was sandwiched between the surface on which the electrostatic electrode paste was printed and the surface on which the heater electrode paste was printed followed by pressing to form a molded body then the pressed body was subjected to hot press firing to prepare an electrostatic chuck this is a technique similar to that shown in fig2 a to be more specific an alumina sintered body on which an electrostatic electrode paste was printed was prepared according to paragraphs 0057 to 0059 of the patent document jp 2009 302571 a this alumina sintered body will ultimately form a dielectric layer of an electrostatic chuck an alumina sintered body on which a heater electrode paste was printed was also prepared according to the description an alumina granulated powder was prepared according to paragraph 0055 of the same publication then the alumina sintered body was placed.