PURPOSE: To prepare a highly pure phenol compound from the hydroperoxide of an isopropylaromatic compound in high recovery ratio, by pretreating the thermal decomposition product of the hydroperoxide with a polyhydric alcohol or its ether to eliminate the by-products and thereafter recycling the product to the distillation system.

CONSTITUTION: A process for the preparation of a phenol compound, comprising acid-decomposition of the hydroperoxide of an isopropylaromatic compound, distillation separation of the useful components, e.g. acetone, a phenol compound, etc., from the product, thermal decomposition of the distillation residue, and recyling of the produced crude phenol compound to the distillation separation process, wherein said crude phenol compound is preliminarily contacted with a polyhydric alcohol or its ether, e.g. ethylene glycol or a polyalkylene glycol, pref. the latter (pref. containing 10W50wt% of water), to form double layers, and the product is recycled to the distillation separation process after removing the hydrocarbon layer from the double layers.