A particle beam delivery system includes a beam delivery line of charged particle and a gantry body supporting the beam delivery line. The gantry body is rotatably supported by a first support and a second support. The gantry body serves to rotate the beam delivery line about a horizontal axis passing through the first and second supports. The gantry body comprises a cantilevered portion configured to support at least a section of the beam delivery line in a cantilevered manner extended beyond the first and second supports. The second support is supported by a structure which is rotatable about a vertical axis passing through the second support, thereby providing clearance for the cantilevered portion of the gantry body when rotating about the horizontal axis. The gantry body may be rotatable about the horizontal axis in 360 degrees, clockwise and/or counterclockwise.
