PROBLEM TO BE SOLVED: To provide a linear acceleration device capable of stably accelerating ion beams from low energy using a semiconductor high-frequency amplifier.SOLUTION: A linear acceleration device 4 of the present embodiment includes: a first linear accelerator 41; a second linear accelerator 42 which is located along an advancing direction of ion beams with respect to the first linear accelerator 41 and on the downstream side in the advancing direction of the ion beams; a beam focusing device which is installed in at least the first linear accelerator 41 and focuses the ion beams: and semiconductor high-frequency amplifiers 45 which are respectively connected to the first linear accelerator 41 and the second linear accelerator 42 to supply high frequency electric power.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT