A needle attachment and detachment assist device includes a frame body, a syringe guide jig, and a needle guide jig. A guide hole is formed in the syringe guide jig. In the needle guide jig, a needle insertion hole is formed on a central axis of the guide hole. The needle insertion hole includes a center hole portion and a rib guide groove. When a syringe is inserted into the guide hole, and a needle member is further inserted into the needle insertion hole, rotation prevention of the needle member is achieved. In this state, when the syringe is rotated in a first direction, the needle member can be clamped to a thread portion of the syringe. When the syringe is rotated in a second direction, the needle member can be loosened.
