In a balanced acoustic wave filter device, first and second acoustic wave
filter sections that are connected in parallel to an unbalanced terminal
are connected to first and second balanced terminals, respectively. The
first and second surface acoustic wave filter sections are configured
such that the phases of the first and second balanced terminals differ by
180 degrees. The first and second acoustic wave filter sections are
longitudinally coupled resonator-type acoustic wave filter sections each
including a plurality of IDTs disposed in a direction in which acoustic
waves propagate. The total number of pairs of electrode fingers of the
IDTs in the second acoustic wave filter section in which the polarities
of electrode fingers that are adjacent to each other in an area in which
IDTs are adjacent to each other are opposite to each other is greater
than the total number of pairs of electrode fingers of the IDTs in the
first acoustic wave filter section in which the polarities of electrode
fingers that are adjacent to each other in an area in which IDTs are
adjacent to each other in the direction in which acoustic waves propagate
are equal to each other.