Abstract: The invention relates to a method (S) for generating a plurality of cold-plasma jets at atmospheric pressure in order to treat a target (2), wherein said method includes the following steps: producing (S1) a primary cold-plasma jet (3) at atmospheric pressure using a plasma source (10); placing (S2) a substrate (20, 21, 30, 32, 34) near the target (2) to be treated, said substrate (20, 21, 30, 32, 34) including at least two through-holes; and passing (S3) the plasma through the through-holes (22) of the substrate (20) such as to generate at least two secondary cold-plasma jets (4) at atmospheric pressure.