A control device for operation of a system for treating a surface of a solid running substrate by dielectric-barrier electrical discharge in a controlled gaseous atmosphere, comprising (A) a system which includes (i) a treatment device through which a substrate to be treated runs at a speed, (ii) the system is connected to the treatment device for supplying the treatment device with a flow of gas, (iii) the system is connected to the treatment device for supplying the treatment device with electrical power in order to produce the electrical discharge and (iv) the system sucking out the gas, (B) a data processing unit capable of receiving, as input, a datum regarding the speed at which the substrate is running through the treatment device, the data processing unit further comprising an output side connected to the system for controlling the electrical power supply system, in order to regulate the flow of gas delivered by the or each of the gas supply system and/or the electrical power delivered by the electrical power supply system to the device as a function of the speed at which the substrate is running through the treatment device, so as to obtain a surface treatment of the substrate with an equivalent quality whatever the speed at which the substrate is running through the treatment.