A sound wave generator is configured to generate ultrasonic waves having a predetermined frequency that chases away vermin. The sound wave generator includes a power supply, a switch, an oscillation circuit, and a speaker. The power supply includes a battery that is a DC power supply and outputs DC power for generating sound waves. The switch is operated by a user of the sound wave generator to switch between supply and non-supply of power from the power supply to the oscillation circuit. When the switch is turned on, the oscillation circuit operates with DC power output from the power supply and oscillates an electrical signal having a predetermined frequency. An organic transistor is used in the oscillation circuit. The speaker converts the electrical signal oscillated by the oscillation circuit into sound waves and outputs the sound waves.