An acoustic-wave ladder filter has a first port, a second port and a ground terminal, and includes a series resonator and a shunt circuit. The series resonator is coupled to and disposed between the first and the second ports in series. The shunt circuit is coupled to and disposed between the series resonator and the grounding terminal, and includes a shunt resonator and a functional circuit. The functional circuit is connected in series with the shunt resonator. The functional circuit includes a resistor having a resistance value. The resistance value is greater than 5 Ohms and is smaller than 50 ohms. The functional circuit may further have an inductance.