PURPOSE: To measure moisture content rapidly and accurately, by a method wherein the componential current of a 90° advance phase with respect to applied voltage in a current flowing through an object to be measured is detected by using a high frequency power source and the componential current having the same phase as the applied voltage is detected by using a low frequency power source.

CONSTITUTION: A moisture measuring apparatus is equipped with a high frequency power source apparatus 11 generating positive phase wave AC voltage with stable value Eh and angle frequency Wh and a low frequency power source apparatus 12 generating positive phase wave AC voltage with stable value E and angle frequency W. The componential current of a 90° advance phase with respect to applied voltage in a current flowing through an object to be measured is detected by using the high frequency power source apparatus 11 and the componential current having the same phase as the applied voltage is detected by the low frequency power source apparatus 12 to make it possible to measure moisture content rapidly and accurately.