Abstract: The utensil provided by the invention comprises an elongated handle having at one end a working head comprising an end-piece in the form of a tapering beak, pointed and upwardly curved, for dislocating and separating the valves through the heel of the shell, and an element for severing the muscle formed by a blade retractable into the handle, assisted by a return spring and sliding in a plane passing between the base and the point of the end-piece. A projection, provided for bearing against the hand holding the oyster and for serving as a guard, is formed from two prongs having the same form as the profile of the end-piece.