Abstract: For a sheet-metal bending press of the kind in which the coaction of a die and a punch causes the metal plate to be bent at an angle, a device is provided, which is capable of detecting the angle of bend of the plate being machined in a continuous way and of generating a signal which has a magnitude proportional to the angle width. The signal can be used either as a continuous angle-checking means, or for driving the automatized operation of the press, or for both functions. The necessity of removing the plate to be bent angularly in order to check the angle progressively produced is entirely eliminated. A zero method can be adopted for taking readings when the front surface of the detector proper of the angle is not exactly coplanar with the resting surface for the plate on the press bed.