This drug delivery device connects a syringe barrel and a drug container by using a closed system by means of an easy operation that can be carried out by employing a simple configuration, and delivers a drug between the syringe barrel and drug container via a first hollow needle member and a second hollow needle member in the closed system. Said device has a first member connected to the cover-side of the drug container, a second member of which one end is connected to the first member and the other end is connected to the syringe barrel, and a volume-variable third member connected to the first member and for adjusting the gas pressure within the drug container. The first, second and third members are connected by means of a fitting mechanism. The tip end part and the base part of the second hollow needle member provided to the second member is secured facing the first member. The first member has the first and third hollow needle members. The second hollow needle member is inserted into the first hollow member by penetrating the elastic members of the first and second members while said elastic members are connected to and abut one another. At the same time, the third hollow needle member is inserted into the cover of the drug container.Linvention concerne un dispositif dadministration de médicament, qui relie un tube de seringue et un récipient de médicament à laide dun système de fermeture au moyen dune manœuvre aisée qui peut être effectuée par lutilisation dune configuration simple et qui administre un médicament entre le tube de seringue et le récipient de médicament via un premier élément daiguille creuse et un deuxième élément daiguille creuse dans le système de fermeture. Ledit dispositif présent un premier élément relié au côté couvercle du récipient de médicament, un deuxième élément dont une extrémité est reliée au premier élément et lautre extrémité est reliée au tube de seringue et un troisième élément à volume variable relié au premier élément et de
