The KiHa 40 series (キハ40系, Kiha-yonjū-kei) is a diesel multiple unit (DMU) train type introduced by Japanese National Railways (JNR) in 1977 and operated by all Japan Railways Group companies on suburban and rural services in Japan.

These were subdivided as shown below, with further variants and modifications made later in their lives by the various JR Group companies.

[1] In 2017, KiHa 40 1009 was taken over by Nishikigawa Railway, that ended operation on the Karasuyama Line by JR East in March 2017.

[5][6] The latest acquisition purchased by the third-sector railway company which has been funded by the local government of Kasai City to purchase a retired unit from JR East which had been recently ended their local services in Gono Line on 2021.

[7][8][9] The local government had been successfully collected their crowdfunding at a cost of about 30 million yen (approx.

The railcar has been successfully remodeled and started began their operation in March 2022 with retaining its former livery used in Gono Line by JR East.

[14] On 27 March 2024, these cars were handed over to the Thai railway operator prior to shipping from Niigata Port.