To provide a method for filtering and producing wood vinegar by removing a tar component, capable of almost completely decomposing and removing liquid solute impurities, such as the tar component, in the wood vinegar, and to provide a bath preparation.

This method for filtering and producing the wood vinegar includes a first process using a descending fluid column A and a second process using a ascending fluid column B connected to the descending column A, wherein crude wood vinegar 1 fed into the descending fluid column A is descended by controlling an inlet flow control valve C and an outlet flow control valve D so as to keep descending pressure at zero, then the descended wood vinegar is pressurized to ascend the ascending fluid column B and subjected to counter aeration with the vinegar spontaneously descending by its own weight to form fine bubble particles, and further the formed fine bubble particles are ascended through the ascending fluid column B, while being made to pass through rice straw bundles 6 and react with them at first, so that the tar component is effectively removed from the crude wood vinegar. The wood vinegar thus obtained is used for the bath preparation as it is.