Device for cleaning teeth which comprises a dental floss fork (2) provided with a grippable handle (3) and with two rods (4) with free ends (4″) spaced from each other and a dental floss (5), which is mounted with a bridge section (5′) between the free ends (4″) of the two rods (4) of the dental floss fork (2). The dental floss (5) has annular extension and the dental floss fork (2) is provided with guide means (6), in which the dental floss (5) is housed, for supporting it along its annular extension. The dental floss (5) is slidably mounted within the guide means (6).