The office was opened on Monday and is headed by Tsunetoshi Minesaki, according to the Center of Registers.
Hitachi Europe CEO Akira Shimizu said last year that Hitachi was looking to expand its operations not only in Lithuania, but also in the other Baltic countries and Scandinavia.
He said that Hitachi's interest in Lithuania was not limited to the planned new nuclear power plant project, adding that the corporation saw high potential in the country for the development of projects in energy, including smart grids, information technologies, infrastructure and healthcare.
Last year, Hitachi Europe started looking for a business development manager for the Baltic countries.
Hitachi has said that the representative office will give priority to Lithuania, followed by the Baltic countries and Scandinavia.
Hitachi is the majority shareholder of Hitachi-GE Nuclear Energy, the Japanese-US group that the Lithuanian government has chosen as a strategic investor in the planned Visaginas nuclear power plant.
The government and Hitachi expect to sign a final agreement on the Visaginas project this year.
Hitachi has a global workforce of about 360,000 people.