An exoskeleton apparatus includes a base unit, a support unit, and upper and lower arm units. The support unit is rotatable about a vertical first axis relative to the base unit. The upper arm unit includes a linking axle, a main arm that has a connecting end rotatable about a horizontal second axis, and a linkage mechanism for rotating the linking axle relative to the main arm about a horizontal third axis. The lower arm unit is rotatable relative to the upper arm unit, and includes a lower arm set co-rotatably coupled to the linking axle, a hand-receiving seat rotatably connected to the lower arm set, and a lower arm receiving seat connected to the hand-receiving seat, and a drive member for rotating the hand-receiving seat about a horizontal fourth axis.
