The present disclosure relates to a particle therapy apparatus for irradiating a target with a charged particle beam and having a particle accelerator and an isocentric gantry rotatable about an axis. The gantry includes a sequence of bending magnets to successively bend and direct the particle beam towards the isocentre of the gantry. A last bending magnet of the sequence is configured to bend the particle beam in a first plane including the isocentre and making a large angle with the axis. The gantry further includes a first scanning magnet arranged upstream of the last bending magnet and configured to scan the particle beam over the target. The apparatus also includes a magnetic resonance imaging (MRI) system having two main magnet units arranged on both sides of the isocentre and configured to generate a main magnetic field parallel to or coaxial with the axis.
