To hang a dental instrument switchably to a vertical state or a horizontal state, to make the head part of the instrument at almost a same position both in a vertically hung state and in a horizontally hung state and to facilitate the pull-out operation of the instrument.

This device is provided with an instrument holder 2 through which a dental instrument hose 21 is passed for holding the dental instrument 20 and holder links 4 and 5 for fixing the instrument holder 2 to a fixing member 3. For the holder links 4 and 5, one end freely turnably supports the instrument holder 2, the other end is freely turnably fixed to the fixing member 3 and the two arm links 4 and 5 change the instrument holder 2 to a vertically holding (chain line) state or a horizontally holding (solid line) state in cooperation. Simultaneously, in the vertically holding state and the horizontally holding state, the head part 20 of the instrument is positioned at almost the same position.