PROBLEM TO BE SOLVED: To provide an orthosis joint device which is good to use and practicable by arbitrarily changing the pivot around movable area of a joint corresponding to the symptom, recovery situation, etc. of the affected part of the patient who wears orthosis.SOLUTION: An orthosis joint device 10 comprises: a first member 12 constituting a portion of orthosis 100; a second member 14 which rotatably connects with the first member 12; a pivot 16 which pivotally connects the first member 12 and the second member 14 in a rotatable manner; and a pivot around movable area setting mechanism 18 which sets plural movable angle ranges around the pivot with respect to the pivot around rotation of the first and second members 12 and 14.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT