PURPOSE: To provide an instrument holder for a dental unit which enables the easy insertion and placement of an instrument for dental treatment connected to an instrument tube along the incised longitudinally long groove of a hanger frame.

CONSTITUTION: Umbrella-shaped roller supporting bodies 14, 14 which freely turnably support a pair of umbrella-shaped rollers 7, 7 oppositely to each other are fixed to the front end 13 of the hanger frame 2 and a pair of guide rollers 4, 4 are freely turnably juxtaposed along the longitudinally long groove 3. In addition, the front ends of roller shafts 5, 5 of a pair of the guide rollers 4, 4 are connected to the umbrella-shaped roller supporting bodies 14, 14 and tension springs 6 for pulling roller shafts 5, 5 to each other are installed to the rear parts of these roller shafts 5, 5. A stopper wall 9 having inverted V-shaped slits 8, 8 in which the rear parts of the roller shafts 5, 5 are inserted supported is erected behind the hanger frame 2.