A matching circuit suitable for adapting electrical impedance simultaneously for at least two pairs of frequencies, between a capacitively coupled plasma reactor as load and a RF generator as source, the first pair of a higher and a lower frequency being a fundamental frequency with one of its harmonics, said matching circuit comprises at least a load and tune L-type stage , the L-type stage comprising: - a first tune circuit connected in series between the source and the load and comprising at least both an inductor (L Tune1 ) and a capacitor (C Tune1 ) in series, - a first load circuit connected, at a first end between the source and said first tune circuit and at a second end to a signal ground, said first load circuit comprising at least both an inductor (L Load1 ) and a capacitor (C Load1 ) in parallel, wherein the component values of the tune and load circuits are chosen such that, for the lower frequency, the matching circuit follows a negative load reactance path in a Smith chart, and for the higher frequency, the matching circuit follows a positive load reactance path in the Smith chart, the negative load reactance path being the one for which the impedance of the part of the matching circuit added in series to the load results in the sum of the two having a negative reactance, whereas the sum of the two has a positive reactance for the positive load reactance path, wherein for the second and each additional pair of frequencies, the L-type stage further comprises : - an additional tune circuit comprising at least both an inductor (L Tune2 ) and a capacitor (C Tune2 ) in series, said additional tune circuit being in parallel to the first tune circuit (L tune1 , C tune1 ) and - an additional load circuit comprising at least both an inductor (L Load2 ) and a capacitor (C Load2 ) in parallel, said additional load circuit being in series with the first load circuit (L Load1 , C Load1 ) the component values of the additional tune and load circuits are chosen such that for the lower frequency of the second and each additional pair of frequencies, the matching circuit follows a negative load reactance path in a Smith chart, and for the higher frequency of the second and each additional pair of frequencies, the matching circuit follows a positive load reactance path in the Smith chart, respectively. - a first tune circuit connected in series between the source and the load and comprising at least both an inductor (L Tune1 ) and a capacitor (C Tune1 ) in series, - a first load circuit connected, at a first end between the source and said first tune circuit and at a second end to a signal ground, said first load circuit comprising at least both an inductor (L Load1 ) and a capacitor (C Load1 ) in parallel, - an additional tune circuit comprising at least both an inductor (L Tune2 ) and a capacitor (C Tune2 ) in series, said additional tune circuit being in parallel to the first tune circuit (L tune1 , C tune1 ) and - an additional load circuit comprising at least both an inductor (L Load2 ) and a capacitor (C Load2 ) in parallel, said additional load circuit being in series with the first load circuit (L Load1 , C Load1 ) the component values of the additional tune and load circuits are chosen such that for the lower frequency of the second and each additional pair of frequencies, the matching circuit follows a negative load reactance path in a Smith chart, and for the higher frequency of the second and each additional pair of frequencies, the matching circuit follows a positive load reactance path in the Smith chart, respectively. <EOS>