PURPOSE: To contrive to be able to lie comfortably at natural attitude with stretching out legs on a leg supporting rack, also be able to support the legs at varied bending angle of legs by a method wherein a leg supporting rack is supported as changeable of pivoting angle with a movable stick.

CONSTITUTION: The upper end of a movable stick 9 which is provided with an engaging part 21 at the lower end thereof is detachably attached as freely pivotable at the left and right both side end of a leg supporting rack 4. A leg supporting rack fixing member 23 provided with upper and lower plural steps on which engaged parts 22 are engaged with the engaging part 21 is attached at the lower location of the movable stick 9 on the side wall of a main body 12. The leg supporting rack is supported horizontally with the movable stick 9 by engaging the engaging part 21 of the movable stick 9 with the highest step of engaged part 22, the location of the leg supporting rack 4 required for legs 2 at lying attitude can be obtained. The engaging part 21 is engaged with the lowest step of the engaged part 22, then the leg supporting rack 4 is hanged down parallel to the side wall of the main body 12 and restored. The leg supporting rack 4 can be supported at inclining position with the movable stick 9 by engaging the engaging part 21 with the middle step of the engaged part 22.