To provide a device for reducing leakage of injection material capable of preventing wasteful consumption of the injection material by restraining leakage of the injection material using an inexpensive and simple structure.SOLUTION: A leakage reduction part 21 reduces the leakage amount of an injection material Mleaking from a storage part 6R storing the material Minto an injection pipe 10 injecting the material Mwhen the storage part 6R oscillates. Besides, the leakage reduction part 21 reduces a volume of a storage space Sfor the material Mexisting near a suction port 10c sucking the material Minto the pipe 10 from the storage part 6R. A volume reduction part 22R is mounted detachably between the right side of an outer peripheral surface in the injection pipe 10 and the right side of a bottom face of the storage part 6R to reduce the volume of the storage space Sfor the material Mexisting therebetween. A volume reduction part 22L is mounted detachably between the left side of the outer peripheral surface of the pipe 10 and the left side of the bottom face of the storage part 6R to reduce the volume of the space Sfor the material Mexisting therebetween.SELECTED DRAWING: Figure 10