A device for removing a needle unit from an injection device, the device for removing including an opening for receiving the needle unit and a locking structure generally associated with the opening, the locking structure formed in at least one rim area along the circumference of the opening, such that the needle unit can be moved in an insertion direction through the opening after it has been inserted into the opening, and when the needle unit is moved counter to the insertion direction, it establishes a locking connection with the locking structure. In one embodiment, the invention includes a container for receiving and containing at least one used needle unit.