of a constant tension regulator of warp threads in a weaving machine the whole device is arranged on frame 5 of the machine the regulator includes a sensor 1 for sensing the tension of warp threads 7 and responds to changes in tension in the warp threads by changing its position i e by a deviation the sensor 1 is connected to an integrator 2 and to a proportional adjustor 3 which are connected to each other in parallel the outputs of said integrator 2 and adjustor 3 are added and transmitted to the control member of the final control element 4 which includes a variable speed gear box this control element 4 responds to the change of position of its control member by a change in angular velocity of its output shaft 9 which is connected by a mechanical transmission a worm 10 and a worm gear 11 to the warp beam the controlled warp threads 7 are thus unwound from warp beam 6 which is rotatably mounted on frame 5 of the machine from the warp beam 6 warp threads 7 are guided via sensor 1 of the regulator and not shown healds of heald shafts the reed the weft inserting mechanism and in the form of a fabric to the withdrawing beam and the remaining known parts of a weaving machine sensor 1 of the regulator is formed by a back.