Provided are X-Y constraining units having excellent yawing attitude precision as well as a stage apparatus and a vacuum stage apparatus, each including the X-Y constraining units. The X-Y constraining units 8 and 9 includes: Y-axis bases 81 and 91 respectively connected to Y-axis sliders 4 and 5 and having a through hole extending along Z direction; X-axis bases 82 and 92 respectively connected to an X-axis guide rail 6; shafts 83 and 93 respectively inserted into the through hole and fixed to the X-axis bases 82 and 92; and a plurality of bearing balls which are located between an inner peripheral surface of each of the through hole and an outer peripheral surface of the shafts 83 and 93, and are arranged so as to circumferentially surround the shafts 83 and 93. Each of the stage apparatus 1 and the vacuum stage apparatus includes the X-Y constraining units.