PURPOSE: To prevent ununiformity in thickness of thin film by forming a spherical top of hole for attracting a semiconductor wafer through projection of such top of hole.

CONSTITUTION: A semiconductor wafer support chuck 1 having the T-shaped section comprises a top surface 2 and a rotatable shaft 3, and the top surface 2 is provided with an annular groove. A rubber O ring 4 is engaged with such annular groove in order to attain closer contactness with a semiconductor wafer 5. The rotatable shaft 3 is capable of rotating at high speed and is provided with a hole 6 connected with a pressure reduction mechanism at the inside thereof. On the other hand, this top surface 2 is formed spherically by forming a protruded part 7 through projection of periphery of a hole 6 in about 0.2mm to 0.3mm from the circumferential end. A semiconductor wafer 5 is coated with liquid source or resist and then the rotating shaft is rotated at high speed in order to form a thin and uniform film 9. Thereby, uniformity of thin film deposited on the semiconductor wafer may be improved.