An artificial resuscitation bag comprising: - a deformable bag comprising a gas inlet and a gas outlet, - a gas conduit in fluid communication with the gas outlet of the deformable bag, and - a pneumatic valve comprising an exhaust port cooperating with a membrane element for controlling the flow of gas exiting to the atmosphere through said exhaust port, said membrane element being arranged into an inner compartment of the pneumatic valve, and further comprising: - an overpressure valve arranged in the gas conduit, - a first one-way valve arranged in the gas conduit between the overpressure valve and the pneumatic valve and - a derivation conduct having: i) a first end fluidly connected to the gas conduit, between the gas outlet of the deformable bag and the overpressure valve, and ii) a second end fluidly connected to the inner compartment of the pneumatic valve, and further comprising: - a first conduit in fluid communication with the gas inlet of the deformable bag, - an oxygen line fluidly connected to said first conduit, one-way admission valve in fluid communication with the ambient atmosphere for allowing ambient air to enter into said first conduit and - a first exhaust valve arranged in the first conduit for venting excess of oxygen in the first conduit to the atmosphere, - a supplementary gas reservoir in fluid communication, via the first conduit element, with the gas inlet of the flexible bag, and - a second one-way valve arranged in the first conduit upstream of the deformable bag and configured to: prevent gas from the deformable bag from flowing backward in the first conduit and escaping via the first exhaust valve, and allow gas from the oxygen line, from the supplementary gas reservoir and from the one-way admission valve to flow via the first conduit into the deformable bag, and wherein the pneumatic valve is arranged in the gas conduit, and further comprises a spring element acting on the membrane element for controlling the flow of gas exiting to the atmosphere through said exhaust port, said spring element being arranged into the inner compartment of the pneumatic valve. - a deformable bag comprising a gas inlet and a gas outlet, - a gas conduit in fluid communication with the gas outlet of the deformable bag, and - a pneumatic valve comprising an exhaust port cooperating with a membrane element for controlling the flow of gas exiting to the atmosphere through said exhaust port, said membrane element being arranged into an inner compartment of the pneumatic valve, - an overpressure valve arranged in the gas conduit, - a first one-way valve arranged in the gas conduit between the overpressure valve and the pneumatic valve and - a derivation conduct having: i) a first end fluidly connected to the gas conduit, between the gas outlet of the deformable bag and the overpressure valve, and ii) a second end fluidly connected to the inner compartment of the pneumatic valve, and further comprising: i) a first end fluidly connected to the gas conduit, between the gas outlet of the deformable bag and the overpressure valve, and ii) a second end fluidly connected to the inner compartment of the pneumatic valve, and further comprising: - a first conduit in fluid communication with the gas inlet of the deformable bag, - an oxygen line fluidly connected to said first conduit, one-way admission valve in fluid communication with the ambient atmosphere for allowing ambient air to enter into said first conduit and - a first exhaust valve arranged in the first conduit for venting excess of oxygen in the first conduit to the atmosphere, - a supplementary gas reservoir in fluid communication, via the first conduit element, with the gas inlet of the flexible bag, and - a second one-way valve arranged in the first conduit upstream of the deformable bag and configured to: prevent gas from the deformable bag from flowing backward in the first conduit and escaping via the first exhaust valve, and allow gas from the oxygen line, from the supplementary gas reservoir and from the one-way admission valve to flow via the first conduit into the deformable bag,