This drug delivery device (1) delivers a drug between a syringe barrel (6) and a drug container (2) while allowing the pressure difference inside and outside of the drug container (2) to be eliminated by use of a removable apparatus. This drug delivery device (1) includes a first member (8) connected to the drug container (2) on the side of a stopper (4), and a second member (38) connected at one end to the first member (8) and connected at the other end to the syringe barrel (6). The first member (8) includes: the male portion (30) of a fitting mechanism which detachably connects the first member (8) and a third member (56) connected to the first member (8) and which is for maintaining the air pressure inside of the drug container (2) constant a first hollow needle member (12) provided with holes in the base portion (16) and the tip portion (14) for transferring a drug and a third hollow needle member (32) provided with air holes in the base portion (36) and the tip portion (34). The second member (38) includes a second hollow needle member (42) provided with holes in the base portion (46) and the tip portion (44) for delivering the drug. The second hollow needle member (42) is inserted into the first hollow needle member (12), and the first hollow needle member (12) and the third hollow needle member (32) are inserted into the stopper (4) of the drug container (2), and the drug is delivered through the first hollow needle member (12) and the second hollow needle member (42).Linvention concerne un dispositif dadministration de médicament (1) qui administre un médicament entre un corps de seringue (6) et un récipient de médicament (2) tout en permettant à la différence de pression à lintérieur et à lextérieur du récipient de médicament (2) dêtre éliminée par utilisation dun appareil amovible. Le dispositif dadministration de médicament (1) de la présente invention comprend un premier élément (8) relié au récipient de médicament (2) sur le côté dune butée (4), et un
