Turning device provided at joint of robot arm includes: shaft cover including tubular wall extending in axial direction； turning shaft inserted into inside of wall of shaft cover and extending in axial direction； bearing causing shaft cover to support turning shaft wherein turning shaft is rotatable about a center axis of turning shaft； and at least one operating wire coupled to turning shaft at inside of shaft cover wall. Shaft cover includes a guide guiding operating wire. Guide is formed to be symmetrical about symmetry plane passing through shaft cover center axis and parallel to axial direction. Each portion of guide which portions are located at both respective sides of symmetry plane includes: outer peripheral portion formed on wall outer surface and extending in axial direction； inner peripheral portion formed along wall inner surface and extending in circumferential direction； and connecting portion connecting outer peripheral portion and inner peripheral portion.
