To provide a manufacturing method of a surface acoustic wave device capable of preventing reduction in the mechanical strength of a connection part caused when a plurality of surface acoustic wave elements are mounted on a mount substrate by flip-chip connection utilizing ultrasonic waves.

An ultrasonic wave is applied to a connected part while changing a forming condition of bumps 15 and a configuration factor of the surface acoustic wave elements 100 when the surface acoustic wave elements 10 are mounted on the mount substrate 20 by connecting the bumps 15 to electrode pads 22. For example, the size of first and second elements 10a, 10b is changed from each other. Thus, it is avoided that the connection part of the surface acoustic wave 10 earlier mounted is resonated to cause reduction in the mechanical strength.