To provide a method of operating dewatering equipment which is capable of easily releasing a clogging state of wastes without stopping its opera tion.

According to this operating method, in case that the wastes are clogged in a casing in spite of attempt to reversely rotate a screw body 2 for dewatering, after attempting, for example, three times, the reverse rotation, stop and forward rotation, open an opening/closing cap 27 disposed at a rear end 1e of the opening/closing case 1 by an opening/closing cylinder device, then reversely rotate the screw body 2 for dewatering and take out the wastes in the clogged state out of a discharge aperture 1f.