According to the inventive method for the operation of a cryogenic tunnel (1) fitted with means (2) for injecting a cryogenic fluid and means for variable-rate extraction (3) of cold gases, at least one temperature probe (21,22) which is located outside the tunnel (1) close to the entrance and/or exit thereof and able to provide a value T (input/output) of the temperature of the gases and at least one second temperature probe (23) located outside the tunnel and able to provide a value T (amb) of the ambient temperature of the premises wherein the tunnel operates are provided and the difference T (amb input/output) is determined between the ambient temperature T (amb) and the temperature T (input/output) which is compared to a predetermined setpoint value To (amb-input/output) in order to act retroactively, according to the result of said comparison, on the rate of extraction of the extraction means (3) in order to establish, if necessary, the value of said temperature difference with regard to the setpoint value To (amb-input/output).