The invention relates to a gas supply device including a supporting frame (2) housing a plurality of cylinders (3) connected such as to form a circuit (4, 5) including a first coupling end (6) connected to the cylinders (3) via a first isolation valve (7) and a second separate coupling end (8) that is connected to the cylinders (3) via a second isolation valve (9) and a pressure release valve (10), the supporting frame (2) including an interface panel (20) comprising at least one opening enabling a user to access the circuit (4, 5), characterized in that the device comprises a member (16) for manually controlling the second isolation valve (9) including a pivoting lever, and in that the interface panel (20) includes a slot (21) for accessing the lever (16), said lever (16) being movable between a first position in which the lever (16) is in the plane of the interface panel (20) or set back from the latter within the volume of the frame (2) and a second position in which at least one portion of the lever (16) projects relative to the interface panel (20) through the slot (21).