The present invention relates to an assembly device for assembling and/or disassembling at least one needle unit (10) and a drug delivery device (30), wherein the assembly device comprises:- a deposition means (26) adapted to bring or to keep the drug delivery device (30) in an assembly position,- a holder (44) for at least one needle unit (10), and- an assembly unit (38) adapted to assemble and/or to disassemble the needle unit (10) and the drug delivery device (30).
