PROBLEM TO BE SOLVED: To provide a prime mover structure of a work vehicle which has a high inhalation capacity of a radiator fan and a high exhaust capacity of a dust discharge fan, suppresses overheat of an engine, and requires a less frequent maintenance/inspection work.SOLUTION: The prime mover structure of a work vehicle includes: an oxidation catalyst device 11 arranged above an engine E at an inner side portion of a machine body along a front/rear direction and oxidizing unburnt fuel in an exhaust gas exhausted from the engine E a front plate 40 arranged in a front part and in an upper side of the oxidation catalyst device 11 and supporting a side panel 6A of an operation part 6 and an operation seat 6F of the operation part 6 a guide plate 42 arranged in a rear part and on an upper side of the oxidation catalyst device 11 and extended on an inner side of the machine body from a rear plate 41 supporting an air cleaner 6G arranged at a rear part of the operation seat 6 and a reaping/threshing clutch lever 6B arranged on the side panel 6A, disposed on an inner side of the machine body than the oxidation catalyst device 11.SELECTED DRAWING: Figure 15
