PURPOSE: To provide a vacuum distillation method and vacuum distillation apparatus appropriate for the distillation and regeneration of combustible solvent after work washing.

CONSTITUTION: In a vacuum distillation apparatus, a trochoid pump 18 or liquid ring vacuum pump as a vacuum pump is provided and further a vacuum gage with a contact 10 for detecting a distillation end point and a distillation residue cooling tank 23 for cooling a distillation residue are provided. A safe and efficient vacuum distillation method for recovering waste work-washing liquid contg. combustible solvent by using the vacuum distillation apparatus is provided.