An electrostatic chuck for holding a wafer includes a ceramic plate of
which one main surface is formed to work as a mounting surface for
mounting the wafer, and electrostatic attraction electrodes formed on a
lower surface of the ceramic plate or in the ceramic plate. A recess
portion having a depth in a range of from 3 to 10 .mu.m is formed on one
main surface of the ceramic plate excluding an outer peripheral portion
thereof. The waviness of a top face of the outer peripheral portion is
set to 1 to 3 .mu.m, a gas groove is provided to a peripheral portion of
a bottom surface of the recess-portion bottom surface, and electrostatic
attraction electrodes are disposed in the ceramic plate disposed below
the bottom surface of the convex portion. In the electrostatic chuck thus
constructed, a high wafer-dechucking sensitivity can be exhibited.