To improve the cooling effect for fuel to improve stability of combustion in an engine, in a fuel cooling device of a diesel engine vehicle, and to protect the fuel cooling device from external force.

A reserver tank (29), whose cross-section extends in the vehicle front-back direction (X), is arranged between a feed fuel pipe (26) and a return fuel pipe (27), and a battery (13), a space part (30), where cooling air (A) flows along the feed fuel pipe (26) and the return fuel pipe (27), is formed between the feed fuel pipe (26) and the return fuel pipe (27), and the reserver tank (29), a heat radiation part (31), which is made of metal pipes, is formed on the feed fuel pipe (26) and the return fuel pipe (27), and the heat radiation part (31) is attached to a metal pipe part (35) among suction pipes (20) via a metal bracket (34) on the vehicle rear side of the space part (30).