The invention is related to the field of medical equipment. Claimed is an automatic injection device (110) with an adaptor for transfer of a fluid medium from a container to a chamber comprising a first assembly including a chamber (116) accommodating fluid medium, said chamber comprising an inner surface and an outlet opening (144); a stopper (112) made of an elastic material, movable inside the chamber and having an outside surface substantially contacting the inner surface over its periphery; and an adaptor able to transfer fluid medium to the chamber where the adaptor includes a means for moving the stopper (112) through the chamber (116), and a means for transfer of fluid medium into the chamber (116) as the stopper (112) moves from the closed outlet opening; the adaptor being able to receive a fluid medium container (132) and to transfer fluid medium from the container to the chamber (116) by means of a fluid medium channel; characterized in that it comprises a second assembly including a detachable drive mechanism, said drive mechanism including an elongated rod that acts directly on the stopper after activation of the drive mechanism, the means for transfer of fluid medium into the chamber (116) comprising a hollow fluid medium transfer needle (128) engageable with the fluid medium container for fluid medium transfer from the fluid medium container through the hollow needle when the stopper is shifted away from the outlet opening; and the hollow needle is able to pierce the stopper (112) so that the hollow needle extends from the container to the chamber to feed fluid medium through the stopper to the chamber (116). Also claimed is a method for introduction of fluid medium into the automatic injection device and a set for injections including the automatic injection device. The invention provides versatility and reduction of labour efforts while using.Изобретение относится к области медицинской техники. Заявлено автоматическое инъекционное устройство (110) с