The Tobu 50000 series (東武50000系, Tōbu 50000-kei) is a DC electric multiple unit (EMU) commuter train type operated by the private railway operator Tobu Railway in Japan since March 2005, manufactured by Hitachi to its "A-train" concept.

The second set differs in having an emergency door in the front ends, and externally resembles the 50050 series used on the Tobu Skytree Line (see below).

It differs from earlier variants in having full-colour LED destination indicators, and is also equipped with ATO for subway operation.

[9] This set differs in having opening windows similar in design to those added to JR East 209 series EMUs.

Externally, the sets feature a blue waistline stripe running the length of each car, with a "TOJO LINE" logo.

[14] A fifth set, 51095, was delivered from Hitachi in September 2010,[15] followed by 51096 in November 2010, in preparation for an increase in the number of TJ Liner services from the start of the revised timetable on 5 March 2011.

[20] The set was reintroduced into service on 12 February 2019, and was used on the first down departure of the new "Kawagoe Limited Express" train category operating on the Tojo Line since the 16 March 2019 timetable revision.

From 3 November 2016, 50050 series set 51055 received a yellow vinyl wrapping livery to mark the 25th anniversary of the cartoon character Crayon Shin-chan.