The present invention relates to a device for automatic injection of a product comprising a container, a needle and a piston. The device includes a housing receiving the container, the container being movable with respect to the housing between an initial position and an insertion position, distally spaced relative to the initial position a safety shield coupled to the housing and movable with respect thereto between a rest position, an activation position, proximally spaced relative to the rest position, and a safety position, distally spaced with respect to the rest position biasing feature for causing the movement of the safety shield to the safety position triggering feature for causing the container to move from its initial position to its insertion position, the triggering feature being releasable by movement of the safety shield to the activation position and, isolating feature for isolating the safety shield from the biasing feature when the safety shield is moved to its activation position.
