A surface acoustic wave apparatus include at least two surface acoustic wave filter devices, each of which includes two or more IDTs. One of the at least two surface acoustic wave filter devices is connected to one of balanced signal terminals, and another of the at least two surface acoustic wave filter devices is connected to the other balanced signal terminal, so as to have a balance-unbalance conversion function. The at least two surface acoustic wave devices are configured to produce a difference in the intensity of the excited SSBW therebetween.