An acoustic wave device includes a first longitudinally-coupled acoustic wave filter having interdigital transducer (“IDT”) electrodes arranged in a propagation direction of acoustic wave, and a second longitudinally-coupled acoustic wave filter having IDT electrodes arranged in a propagation direction of acoustic wave. In the IDT electrodes of the first longitudinally-coupled acoustic wave filter, a comb-shaped electrode connected to an input port and another comb-shaped electrode connected to an output port are disposed in an in-phase relation. In the IDT electrodes of the second longitudinally-coupled acoustic wave filter, a comb-shaped electrode connected to an input port and another comb-shaped electrode connected to an output port are disposed in an anti-phase relation. This acoustic wave device has an excellent attenuation characteristic while maintaining a preferable insertion loss.