NO delivery device for supplying an NO-containing gas, comprising: - an NO injection line for conveying the NO-containing gas, - a valve device arranged on the injection line in order to control the circulation of the NO-containing gas in the injection line, said valve device being configured to be normally in a closed position for preventing any circulation of gas in the injection line, - a flow rate measurement device arranged on the injection line in order to perform one or more measurements of the flow rate of the NO-containing gas circulating in the injection line, - an emergency line which connects fluidically to the injection line upstream and downstream of the valve device, said emergency line comprising an emergency solenoid valve configured to be normally in an open position in order to permit a circulation of gas in the emergency line, and a flow rate control device forming or comprising a system with a proportional calibrated orifice, and - operating means configured to cooperate with the emergency solenoid valve, the flow rate control device, the valve device and the flow rate measurement device, and in which, in the event of a malfunction causing shutdown of all cooperation with the operating means: - the emergency solenoid valve is configured to pass to an open position in order to permit a circulation of gas in the emergency line, - the valve device is configured to pass to a closed position in order to stop all circulation of gas in the injection line, and - the flow rate control device is configured to supply the gas at a pre-fixed emergency flow rate of gas, where said emergency flow rate of gas: ∘ is determined by the operating means on the basis of at least one gas flow rate measurement supplied by the flow rate measurement device, during a normal functioning of the device prior to said malfunction, and ∘ is pre-regulated through command of said flow rate control device by the operating means, during said normal functioning of the device. - an NO injection line for conveying the NO-containing gas, - a valve device arranged on the injection line in order to control the circulation of the NO-containing gas in the injection line, said valve device being configured to be normally in a closed position for preventing any circulation of gas in the injection line, - a flow rate measurement device arranged on the injection line in order to perform one or more measurements of the flow rate of the NO-containing gas circulating in the injection line, - an emergency line which connects fluidically to the injection line upstream and downstream of the valve device, said emergency line comprising an emergency solenoid valve configured to be normally in an open position in order to permit a circulation of gas in the emergency line, and a flow rate control device forming or comprising a system with a proportional calibrated orifice, and - operating means configured to cooperate with the emergency solenoid valve, the flow rate control device, the valve device and the flow rate measurement device, - the emergency solenoid valve is configured to pass to an open position in order to permit a circulation of gas in the emergency line, - the valve device is configured to pass to a closed position in order to stop all circulation of gas in the injection line, and - the flow rate control device is configured to supply the gas at a pre-fixed emergency flow rate of gas, where said emergency flow rate of gas: ∘ is determined by the operating means on the basis of at least one gas flow rate measurement supplied by the flow rate measurement device, during a normal functioning of the device prior to said malfunction, and ∘ is pre-regulated through command of said flow rate control device by the operating means, during said normal functioning of the device. ∘ is determined by the operating means on the basis of at least one gas flow rate measurement supplied by the flow rate measurement device, during a normal functioning of the device prior to said malfunction, and ∘ is pre-regulated through command of said flow rate control device by the operating means, during said normal functioning of the device.