To provide a dental floss holder reducing the number of components by integrally molding a locking mechanism of the dental floss holder with a body together.

A floss to be supplemented for every roll unit is pulled out from a start end, and held in a state suited to interdental cleaning. Then, for retaining a necessary tension, a core of a roll shaft is fixed to a part having an engageable/fittable shape from the outside, and the start end is fixed by a grip mechanism of the body. The floss depleted after the use is cut off with a cutter and disposed. A supplement procedure is a simple operation of just inserting the rolled floss into a receiving shaft. This configuration further improves usability.