History
Kokkai-gijidō-mae Station opened on 15 March 1959 as a station on the Teito Rapid Transit Authority (TRTA) Marunouchi Line, between Kasumigaseki and Shinjuku. It is located in Nagatachō, Chiyoda, adjacent to the National Diet Building from which the station takes its name. The Chiyoda Line platforms opened on 20 October 1972. On 30 September 1997 the Namboku Line was extended from Yotsuya to Tameike-Sannō and the Ginza Line's Tameike-Sannō Station also opened, enabling fare-paid transfers between the four lines through an underground passage; the two stations are treated as a single station for fare-calculation purposes. The station facilities were inherited by Tokyo Metro after the privatization of the TRTA on 1 April 2004. PASMO IC card use began on 18 March 2007, and a departure melody was introduced on the Chiyoda Line platforms on 27 October 2018.
History summarized from Japanese & English Wikipedia · last reviewed 2026-05-22.
Notes
The Chiyoda Line platforms sit 37.9 metres below ground, making this the deepest station in the Tokyo Metro network (a number of Toei Oedo Line stations are deeper). On the Marunouchi Line side, the station carries a clause from its lease: because the platforms lie beneath grounds owned by the House of Representatives, the chamber may order the station closed at short notice for security reasons — a power exercised during the 1960 Anpo protests, when on 23 April 1960 trains briefly passed through without opening their doors.