An optical module includes a housing, a Peltier device, a semiconductor light-generating device, an optical waveguide, and a power supply circuit device. The housing has first and second power supply terminals. The Peltier device is provided in the housing. The semiconductor light-generating device is provided on the Peltier device. The optical waveguide is optically coupled to the semiconductor light-generating device. The power supply circuit device is provided in the housing and connected to the semiconductor light-generating device. The semiconductor light-generating device and Peltier device are connected in series between the first and second power supply terminals. In the light-generating module, current flows in one of the semiconductor light-generating device and the Peltier device, and then the current flows in the other of the semiconductor light-generating device and the Peltier device.