The thinning rate of the remaining liquid film on rotating substrates with different static contact angles was measured. It was found that the thinning rate of a liquid film increased when the static contact angle between the liquid and the substrate increased. Emslie's equation was modified to account for the effect of the static contact angle. Then it was shown that the thinning rate of the remaining liquid film predicted by the modified Emslie equation agreed well with the measured thinning rate. It is therefore concluded that we can use the equation to determine the appropriate processing time for blowing away a liquid film at a static contact angle.