In 1934 the former station Montparnasse did not fulfill the necessities of the growing traffic and at the same time the city government was planning to reorganize the neighborhood and reconstruct a new station. 
Due to different reasons the project was delayed and only in 1969 the plan of reorganize the neighborhood, move the station, create new streets and improve the old ones was developed.
The construction of this tower was part of this plan. Although there was controversy, the project was finally done in 1973 when it opened its doors.
The Montparnasse tower measures 209 meters and has 59 floors (including the flat roof). There is a restaurant in the 56th floor. There are 52 floors of offices and a total area of 90.000 m2. Plus, 5,000 persons work there.
The handrail of the flat roof can be unloads in only 120 seconds to turned it into a helicopter platform.