To reduce internal heating in a superconducting magnetic device with a light and simple structure, which is accompanied with minute mechanical high frequency vibration corresponding to relative vibration of a supporting beam and the superconducting magnetic device.

In this carriage frame which supports a pair of superconducting magnetic devices 7 elastically by a supporting beam 8, the rigidity (E.A/L) of the supporting beam 8 per one carriage is 20 tonf/mm or higher, a viscoelasticity body 20 is disposed at the connection part between the superconducting magnetic device and the supporting beam, and a spring constant (k) in its compressing direction is in a range of 0.2kgf/mm<k<4kgf/mm per 1cm2. In the shape of the viscoelasticity body 20, it is preferable to have such a shape as at least either of the facing surfaces of the supporting beam comes into discrete contact. Upper and lower supporting beams adjacent to each other may be connected in such a form as to dispose the viscoelastic body.