A longitudinally-coupled-resonator-type surface acoustic wave filter that performs conversion between an unbalanced signal and balanced signals, comprising a single unbalanced terminal that transmits the unbalanced signal, a pair of balanced terminals that transmit the balanced signals, a piezoelectric substrate, a first surface acoustic wave filter unit that includes, on the piezoelectric substrate, a first IDT arranged on a central axis (x) that is orthogonal to a propagation direction of surface acoustic waves, a second IDT and a third IDT that are arranged on either side of the first IDT in the propagation direction of the surface acoustic waves of the first IDT, and a first reflector and a second reflector that are arranged such that the second IDT and the third IDT are interposed therebetween in the propagation direction of surface acoustic waves of the first IDT, a second surface acoustic wave filter unit that includes, on the piezoelectric substrate, a fourth IDT that is arranged so as to be spaced apart from the first IDT by a certain distance in a direction in which the central axis extends, a fifth IDT and a sixth IDT that are arranged on either side of the fourth IDT in the propagation direction of the surface acoustic waves of the fourth IDT, and a third reflector and a fourth reflector are arranged so that the fifth IDT and the sixth IDT are interposed therebetween in the propagation direction of the surface acoustic waves of the fourth IDT, an unbalanced signal wiring line that branches from the unbalanced terminal and is connected to a comb tooth shaped electrode of the second IDT and a comb tooth shaped electrode of the third IDT on a side closest to the unbalanced terminal, a pair of balanced signal wiring lines that connect the balanced terminals and the second surface acoustic wave filter unit to each other, a pair of interstage wiring lines that connect the first surface acoustic wave filter unit and the second surface acoustic wave filter unit to each other, and first and second ground wiring lines (40d,41d) that connect the first surface acoustic wave filter unit and the second surface acoustic wave filter unit to a ground potential, wherein the first IDT includes a first central floating comb tooth shaped electrode on the side closest to the unbalanced terminal and a pair of first divided comb tooth shaped electrodes obtained by dividing a comb tooth shaped electrode on a side farthest from the unbalanced terminal along the central axis (x), the pair of first divided comb tooth shaped electrodes are connected to the second surface acoustic wave filter unit by the interstage wiring lines, a comb tooth shaped electrode of the second IDT and a comb tooth shaped electrode of the third IDT on a side farthest from the unbalanced terminal are connected respectively to the first and second ground wiring lines (40d,41d), which ground wiring lines are located on the opposite sides of the interstage wiring lines from the central axis (x), sandwiching the interstage wiring lines, the fourth IDT includes a pair of second divided comb tooth shaped electrodes obtained by dividing a comb tooth shaped electrode on a side closest to the balanced terminals along the central axis (x), the pair of second divided comb tooth shaped electrodes are respectively connected to the balanced terminals by the balanced signal wiring lines, the pair of first divided comb tooth shaped electrodes are respectively connected to a comb tooth shaped electrode of the fifth IDT and a comb tooth shaped electrode of the sixth IDT on the side farthest from the balanced terminals by the interstage wiring lines, and the first and second ground wiring lines are connected respectively to a comb tooth shaped electrode of the fifth IDT and a comb tooth shaped electrode of the sixth IDT on a side closest to the balanced terminals.