A method for generating a plasma in a continuous manner using a microfluidic or millifluidic device comprising: - a support made at least partially of a dielectric material, the support comprising a first inlet adapted to be connected to a first reservoir containing gas, a second inlet adapted to be connected to a second reservoir containing liquid, an outlet adapted to be connected to a receiver container containing gas and/or liquid, and a main microchannel or millichannel present in the dielectric material allowing the liquid and the gas to flow from the inlets towards the outlet, - one or several ground electrode(s) embedded in said dielectric material and extending along the main microchannel or millichannel, and - one or several high-voltage electrode(s) embedded in said dielectric material and extending along the main microchannel or millichannel, wherein the high-voltage electrode(s) and the ground electrode(s) are located on opposite sides of the main microchannel or millichannel so as to be able to generate an electric field inside the main microchannel or millichannel, the method comprising the steps of: (a) providing a liquid and making the said liquid circulating through the main microchannel or millichannel of the microfluidic or millifluidic device, (b) providing a gas and making bubbles of said gas in the said liquid so that the gas bubbles circulate with the liquid through the main microchannel or millichannel of the microfluidic or millifluidic device, (c) applying a high voltage between the high-voltage electrode(s) and the ground electrode(s) so as to generate a plasma in the bubbles circulating through the main microchannel or millichannel of the microfluidic or millifluidic device, the bubbles remaining in a plasma state all along their travel in the main microchannel or millichannel between the ground and high-voltage electrodes. - a support made at least partially of a dielectric material, the support comprising a first inlet adapted to be connected to a first reservoir containing gas, a second inlet adapted to be connected to a second reservoir containing liquid, an outlet adapted to be connected to a receiver container containing gas and/or liquid, and a main microchannel or millichannel present in the dielectric material allowing the liquid and the gas to flow from the inlets towards the outlet, - one or several ground electrode(s) embedded in said dielectric material and extending along the main microchannel or millichannel, and - one or several high-voltage electrode(s) embedded in said dielectric material and extending along the main microchannel or millichannel, wherein the high-voltage electrode(s) and the ground electrode(s) are located on opposite sides of the main microchannel or millichannel so as to be able to generate an electric field inside the main microchannel or millichannel, (a) providing a liquid and making the said liquid circulating through the main microchannel or millichannel of the microfluidic or millifluidic device, (b) providing a gas and making bubbles of said gas in the said liquid so that the gas bubbles circulate with the liquid through the main microchannel or millichannel of the microfluidic or millifluidic device, (c) applying a high voltage between the high-voltage electrode(s) and the ground electrode(s) so as to generate a plasma in the bubbles circulating through the main microchannel or millichannel of the microfluidic or millifluidic device, the bubbles remaining in a plasma state all along their travel in the main microchannel or millichannel between the ground and high-voltage electrodes.