Abstract: A dental floss holder, having a floss dispensing function, a floss holding function and a floss cutting function, is disclosed. In the holder, the floss holding arm, having two floss guide stems, has a structure agreeable with an oral cavity. In addition, an externally-threaded floss chamber is closed by an internally-threaded cap. A floss drum, held on a shaft in the chamber, is normally stopped by a compression force generated by both the chamber and the cap when the cap is fully tightened on the chamber. However, the floss drum is selectively released from the compression force and is rotatable around the shaft when the cap is loosened. In the floss holder, the free end of the floss is firmly fixed by an internally-threaded fixing plug movably engaging with an externally-threaded projection, thus being almost completely prevented from being unexpectedly released while drawing between the teeth. The floss holder also has a cutter used for removing a used part of the floss.