To provide a solvent purifier by which a filtering apparatus can periodically be purified by comprehending the number of times of washing operation by a leaning apparatus with a simple configuration.

In the solvent purifier 3, a pressure switch 26 detects a pressure of a solvent which flows into a first filter device 8 in a circulation path 45. Thus, based on the output of the pressure switch 26, the number of times of washing operation by a dry cleaner 2 can be comprehended by the side of the solvent purifier 3. Thus, in the solvent purifier 3, a control part 46 is capable of determining the purifying time of the first filter device 8 on the basis of the output of the pressure switch 26. As the result, without remodeling the dry cleaner 2, the number of times of the washing operation by the dry cleaner 2 is grasped by the side of the solvent purifier 3 by a simple constitution of providing the pressure switch 26 to the solvent purifier 3, and the first filter device 8 is purified regularly.