[en] The invention refers to accelerator technique and can be applied in heavy charged particle linear accelerators on H-wave. Besides, the device proposed can be applied as a decelerating system of SHF electrovacuum devices with prolonged interaction. The invention is aimed at HF-power loss reduction. The linear accelerator accelerating system on H-wave is produced in the form of a hollow cylindrical resonator with comb-like holders, fixed on its internal surface along the generatrices diametrically to each other, on which drift tubes equipped with an element for high-frequency power input, are mounted along the longitudinal resonator axis and coaxially to it. To reduce the losses in structure the resonator is separated into single galvanically linked sections performed with the capability of rotation relative to each other around the longitudinal axis. 5 figs