To stably hold a rotary shaft by providing superconducting magnetic levitation holding mechanisms on both upper and lower ends of the rotary shaft.

A sample 32A is axisymmetrically supported with a vertical rotary shaft 31, and the upper and lower ends of the shaft are magnetized into a N-pole and a S-pole. The upper and lower parts of the rotary shaft 31 are non-contactly supported with upper and lower non-contact superconductive bearings 33, 34 by Meissner effect. The upper and lower ends of the shaft 31 are magnetized into the N-pole and the S-pole. When the bearings 33, 34 are in the superconductivity state, the shaft 1 receives resiliency at the upper and lower end by Meissner effect so as to be held non-contactly. A spur gear 35 is fixedly secured to the shaft 31, and a drive gear 36 is fitted to the output shaft of a motor 37. At starting, the motor 37 drives the gears 36, 35, and when fixed rotation is given to the shaft 31, the motor 37 is moved so as to separate the gear 36. Thereafter the degree of vacuum is measured similarly to a customary case. Because the rotary shaft 31 is non-contactly supported at the upper and lower ends in this way, precession or hunting is not generated.