[en] The invention is related to detectors of elementary particles and atomic nuclei and can be used at physical laboratories of experimental investigations into elementary particles and atomic nuclei. The described device for measuring kinetic energy of ion beam contains an energy absorber made of wire in the net form. Wire diameter is comparable with ion path length. A sensitive ohmmeter connected with the net is incorporated into the device. The device suggested measures accelerated ion energy at high accuracy. Due to effect linearity the device is slightly sensitive to the form of beam distribution which is espearcially important during stt-up and adjustment of heavy-ion accelerators. As the frame resistance is measured, the device is insensitive to different types of noises and it is useful when operating the accelerator in pulsed operation