To provide a system for inspecting a diesel engine fuel injection system for microleaks capable of accurately determining whether or not fuel is leaking.

The microleak inspection system includes a cranking device which causes cranking of a diesel engine on an engine assembly line; a mixer for mixing fuel with fluorescent material and supplying the mixture to the diesel engine; an ultraviolet lamp for applying ultraviolet rays to areas around the diesel engine fuel injection system; an ID system which receives data on the determination as to whether fuel is leaking which is made based on changes in hue around the fuel injection system while the ultraviolet lamp applies ultraviolet rays to the areas around the system; and a PLC which receives from the ID system the data on whether or not fuel is leaking and controls the drive of the system and the devices of the engine assembly line depending on whether or not fuel is leaking.