The invention relates to a transfer device (10) for transferring a fluid from a first container (40) into a second container (50), comprising a connection element (11) that has a transfer channel (13) able to be opened and closed by a blocking element (20), as well as two connection adapters (30, 31) each comprising a hollow needle (32), a hollow needle channel (33) that passes throughout each of said two hollow needles (32) and said transfer channel (13) being continuously interconnected in the longitudinal axial direction (12) of the transfer device (10). The blocking element (20) is equipped with an unlocking safety element (25) and, in the starting position, is installed in said connecting element (11) in the locked closing position (100).
