A balanced filter comprising: a filter that has a first and a second unbalanced signal terminal (In, T1), wherein said filter is a ladder filter which is connected between the first (In) and second unbalanced terminals and comprises a plurality of series-arm resonators (S1-S4) and a plurality of parallel-arm resonators (P1-P4); and a lumped parameter balun with two balanced terminals (T21,T22) and an unbalanced terminal connected to the second unbalanced terminal of the filter, wherein the balun outputs signals with different phases generated based on a signal input from the second unbalanced signal terminal of the filter or outputs a signal to the second unbalanced signal terminal of the filter generated based on signals with different phases input to its balanced terminals (T21,T22), the lumped parameter balun including: a first capacitor that is connected in series between the unbalanced terminal and one of the two balanced terminals, and a first inductor that is connected in series between the one of the two balanced terminals and ground; and a second inductor that is connected in series between the unbalanced terminal and the other one of the two balanced terminals, and a second capacitor that is connected in series between the other one of the two balanced terminals and a common node; said balanced filter being characterized in that: said common node is shared by the ground sides of all of said plurality of parallel-arm resonators (P1-P4) of the filter and in that said balanced filter further comprises: a ground inductor that is connected in series between said common node and the ground, wherein said first inductor is not connected to the ground via said common node. a filter that has a first and a second unbalanced signal terminal (In, T1), wherein said filter is a ladder filter which is connected between the first (In) and second unbalanced terminals and comprises a plurality of series-arm resonators (S1-S4) and a plurality of parallel-arm resonators (P1-P4); and a lumped parameter balun with two balanced terminals (T21,T22) and an unbalanced terminal connected to the second unbalanced terminal of the filter, wherein the balun outputs signals with different phases generated based on a signal input from the second unbalanced signal terminal of the filter or outputs a signal to the second unbalanced signal terminal of the filter generated based on signals with different phases input to its balanced terminals (T21,T22), the lumped parameter balun including: a first capacitor that is connected in series between the unbalanced terminal and one of the two balanced terminals, and a first inductor that is connected in series between the one of the two balanced terminals and ground; and a second inductor that is connected in series between the unbalanced terminal and the other one of the two balanced terminals, and a second capacitor that is connected in series between the other one of the two balanced terminals and a common node; a first capacitor that is connected in series between the unbalanced terminal and one of the two balanced terminals, and a first inductor that is connected in series between the one of the two balanced terminals and ground; and a second inductor that is connected in series between the unbalanced terminal and the other one of the two balanced terminals, and a second capacitor that is connected in series between the other one of the two balanced terminals and a common node; said balanced filter being characterized in that: said common node is shared by the ground sides of all of said plurality of parallel-arm resonators (P1-P4) of the filter and in that said balanced filter further comprises: said common node is shared by the ground sides of all of said plurality of parallel-arm resonators (P1-P4) of the filter and in that said balanced filter further comprises: a ground inductor that is connected in series between said common node and the ground, wherein said first inductor is not connected to the ground via said common node.