The 10-000 series operated on the Toei Shinjuku Line between Shinjuku and Motoyawata, and also on inter-running services over the Keio Line from Shinjuku as far as Hashimoto on the Keio Sagamihara Line.

[1] Passenger accommodation consisted of longitudinal bench seating throughout.

[2] The prototype set, 10-010, was built in 1971, and initially tested on the Toei Mita Line.

This consisted of adding external speakers, replacing the original roller blind destination indicators with LED indicators, moving the body side destination indicators from the ends to a central position, and adding interior passenger information displays.

[6] Source:[5][7] The original six-car sets were later lengthened to eight cars with the addition of pairs of 3rd-batch (14 vehicles built in 1986 by Hitachi) and 5th-batch (22 vehicles built between 1988 and 1989 by Kawasaki Heavy Industries) cars.