THE PURPOSES OF THE PRESENT INVENTION ARE TO PROVIDE A METHOD FOR EFFICIENTLY REDUCING WATER CONTENT OF AN OBJECT TO BE TREATED THAT CONTAINS WATER WITHOUT REQUIRING A HIGH-TEMPERATURE ENVIRONMENT SUCH AS ONE EXCEEDING THE BOILING POINT OF WATER, AND TO PROVIDE ANOTHER METHOD FOR EFFICIENTLY EXTRACTING AN OIL-SOLUBLE SUBSTANCE FROM AN OBJECT TO BE TREATED THAT CONTAINS WATER AND THE OIL-SOLUBLE SUBSTANCE, WHICH COMPRISES THE SAME TREATMENT STEPS AS THOSE IN THE ABOVE METHOD FOR EFFICIENTLY REDUCING WATER CONTENT. A METHOD FOR REDUCING WATER CONTENT OF AN OBJECT TO BE TREATED AND/OR EXTRACTING AN OIL-SOLUBLE SUBSTANCE IN THE OBJECT TO BE TREATED INTO OIL IS PERFORMED, WHICH METHOD IS CHARACTERIZED IN THAT THE OBJECT TO BE TREATED CONTAINING WATER OR WATER AND THE OIL-SOLUBLE SUBSTANCE IS MIXED WITH THE OIL AT A TEMPERATURE THAT IS LOWER THAN THE BOILING POINT OF WATER, AT WHICH TEMPERATURE THE OIL IS LIQUID. (FIG. 1)
