A reactance filter comprising suppression in the stop band comprises an input connection (1) for applying an input signal (ES), an output connection (A100) for outputting an output signal (TS), at least series resonator (11, 12, 13, 14), which is connected in a signal path (SP) between the input connection (1) and the output connection (A100), a parallel resonator (21), which is connected between the signal path (SP) and a connection (M) in order to apply a reference potential, and an inductor (31), which is connected in series to the parallel resonator (21). A capacitor (50) is connected by means of one connection (A50a) between the at least one parallel resonator (21) and the inductor (31) and by means of the additional connection (A50b) to the output connection (A100). By connecting the reactance filter as a transmission filter in a duplexer component, the isolation in the receiving band of the duplexer component can be improved.