The is an electric multiple unit (EMU) train type operated by the private railway operator Keikyu on commuter services in the Tokyo area of Japan. First introduced in 1994, a total of eight 8-car sets and six 4-car sets were built by Tokyu Car Corporation and Kawasaki Heavy Industries to replace the ageing 1000 series sets on limited express services.
The 600 series is primarily operated on the Keikyu Main Line. They are also used on inter-running services to the Toei Asakusa Line, Keisei Main Line, Hokuso Line, and the Narita Sky Access Line. Four-car sets are occasionally used on the Keikyu Daishi Line.
, the fleet consists of eight 8-car sets and six 4-car sets (classified 650 series).
The eight-car sets 601 to 607 are formed as follows, with six motored (M) cars and two trailer (T) cars.
The eight-car set 608 is formed as follows, with four motored (M) cars and four trailer (T) cars.
The two "Tp1" cars are each fitted with two single-arm pantographs.
The four-car sets are formed as follows, with two motored (M) cars and two trailer (T) cars.
The "Tp2" car is fitted with two single-arm pantographs.
The first batch of sets introduced featured transverse seating bays throughout. While most of the seating was fixed, some seats were partially retractable. Later sets featured longitudinal seating. From 2004, the earlier sets were modified with some transverse seating bays replaced by longitudinal seats.
Set 606 received a special "Blue Sky Train" livery in March 2005 to commemorate the opening of Haneda Airport Terminal 2.
The 600 series underwent refurbishment from August 2009 to March 2014. Modifications included were replacing the wiper cover with a slit of the model number (similar to those found on the 2100 series and N1000 series), narrower front-end skirts, LED side lights, and a pair of LCD information screens above the doorways.