This invention relates to a device (10) for taking at least one sample of soft tissue from an organ, said device comprising a body (11) and a needle (12) arranged in the body and extending at least partly outside the body through the front end of the body, the needle is formed by a stylet (13) and a cannula (14) coaxial with said stylet, said device comprising a mechanism for arming the needle, designed for sequentially moving the stylet (13) and then the cannula (14) from a rest position to a shooting position wherein the stylet and the cannula are retracted towards the rear end of the body, and a triggering mechanism designed to release the stylet then the cannula and to allow their displacement from the shooting position to the rest position, the cannula being coupled to a cannula slider comprising at least one retaining element for engaging with the cannula slider in a shooting position, the stylet being coupled to a stylet slider (30) comprising at least one retaining element (32) for engaging with the stylet slider in a shooting position and means for unlocking (34) the cannula slider, characterized in that the mechanism for arming the cannula further comprises means for separating the means (34) for unlocking the cannula slider and said retaining element (26) for engaging with the cannula and at least one security element (36) designed for engaging with the stylet slider (30) in a position in which the means (34) for unlocking the cannula slider is separated from the retaining element (26) for engaging with the cannula slider (24) in a shooting position.
