The invention relates to a filtering network in HR-Si silicon technology, defined by at least one cut-off frequency FC and comprising an input terminal P1 for receiving the signal to be filtered and an output terminal P2 for delivering a filtered signal. The network comprises a first ground line M1 connected by its ends to first and second ground points Gr1, Gr2 connected directly to the ground plane, a second ground line M2 connected via its ends to third and fourth ground points Gr3, Gr4 directly connected to the ground plane, a plurality of L/C resonant elements Lr1/Cr1, Lr2/Cr2, Lr3/Cr3 connected in parallel and linked via one end to one of the two ground lines L1, L2 and via the other end between them, by means of coupling inductors Ls1, Ls2, Ls3 which thus create transmission zeros. Since each ground line (M1, M2) forms inductive elements (Lm1, Lm2, Lm3) by inductors, the network comprises capacitive elements (Cm1, Cr'1) in series with at least some of said inductive elements (Lm1, Lm2, Lm3), the capacitance of the capacitive elements being chosen so that the resonant frequency of the inductive and capacitive elements in series corresponds to a frequency lying outside the pass band.