To provide an optical module, reducing a power consumption.

The optical module 1a is provided with a housing 4, a Peltier element 24, a semiconductor optical element 34, a light waveguide passage 8 and an electric power supplying circuit element 48. The housing 4 is provided with a first power supply terminal and a second power supply terminal. The Peltier element 24 is arranged in the housing 4. The semiconductor optical element 34 is arranged on the Peltier element 24. The light waveguide passage 8 is optically connected to the semiconductor optical element 34. The power supply circuit element 48 is arranged in the housing 4 and is connected to the semiconductor optical element 34. The semiconductor optical element 34 and the Peltier element 24 are provided in series between the first and second power supply terminals. In the optical module 1a, an electric current, conducted to flow through the semiconductor optical element 34 and the Peltier element 24 of one side, is conducted to flow also through the semiconductor optical element 34 and the Peltier element 24 of the other side.