rotary body 3 has been adjusted i e by correcting focal position errors of the pickup or the like note that the present invention can be applied to any type disk recording apparatuses disk reproducing apparatuses and disk recording and reproducing apparatuses further while the example in which both squareness errors and misalignments are adjusted has been described in the aforementioned embodiment it may be so designed to adjust only squareness errors or only misalignments still further the magnetic bearing means may be constructed so as to adjust only the upper side or lower side position of the rotary body 3 in the radial direction for example it may also be so designed that the upper side position of the rotary body 3 in the radial direction is magnetically supported and adjusted by the electromagnets v 1 v 3 w 1 and w 3 shown in fig6 and the lower side position of the rotary body 3 is supported using bearings other than the magnetic bearings such as pivot bearings however if the magnetic bearing means is used to support the positions of the rotary body 3 in both radial and axial directions the rotary body 3 can be supported in a noncontact.