Method for producing polyether polyols

The invention provided a process for producing a polyether polyol compound, which is a process for stably producing the polyether polyol compound by converting a diester of a polyether polyol to a polyether polyol compound while inhibiting deposition on the inner wall of the reactor. The process for polyether polyol compound production comprises conducting the alcoholysis reaction of a diester of a polyether polyol with a C1-4 alkanol in the presence of an alkali-metal alkoxide catalyst to convert the diester into a polyether polyol compound, and is characterized in that the C1-4 alkanol contained in the polyether polyol compound yielded is returned to the reaction system while keeping the water content in the alkanol at 100 ppm or lower.