The present invention discloses a particle beam therapy system (2) comprising a configuration of magnetic fields to enable the delivery of a particle beam (12) for particle radiation therapy to a target volume in a patient from a variety of different treatment angles (26), said system (2) comprising: a) a particle beam (12) directed towards an active static magnetic field region (40) wherein the direction of the incoming particle beam (12) is substantially perpendicular to the direction of the magnetic field (H) in the active magnetic field region (40)； b) said active magnetic field region (40) comprising a plurality of magnets (4, 4a to 4c) and/or coils (6, 8, 10) being disposed to generate a cylindrically shaped magnetic field system filled with magnetic fields being oriented substantially in the axial direction of the cylindrically shaped magnetic field system, said active magnetic field region (40) comprising an outer radial guiding field region (16) and an inner radial bending field region (18)； c) the plurality of magnets (4, 4a, 4b) and/or coils (6, 8, 10) are distinguished into: c1) an arc scan magnet system (4, 4a, 4b, 4c) being located at an outer edge of the cylindrically shaped magnetic field system； said arc scan magnet system (4, 4a, 4b, 4c) effecting a radial displacement and angle to the particle beam (12), determining the location where the particle beam (12) enters the guiding field region (16)； c2) a first number of coils (6), optionally embedded in an iron enclosure (36), generating a static magnetic guiding field for the incoming particle beam (12) that has been initially deflected by the arc scan magnet system (4, 4a, 4b), said magnetic guiding field being predominantly effective in the outer radial guiding field region (16) of the cylindrically shaped magnetic field system and enclosing the inner radial bending field region (18)； c3) a second number of coils (8, 10), optionally embedded in an iron enclosure (36), generating a static magnetic b
