A discharge straw cutting device for cutting discharge straw after threshing treatment, comprising: a drive blade having a plurality of cutting blades supported on the drive shaft； a support blade having a plurality of support blades supported on the cutting shaft； and a drive blade and a support blade. In a combine with a case, the cutting blade can be replaced quickly with a small number of people. The driving blade 34 has a state in which both ends of the drive shaft are supported on the left and right side walls of the case 31, and one end of the drive shaft is supported on the left side wall, while the other end of the drive shaft protrudes out of the case 31. It is comprised so that a state can be changed in the protruding state. Further, in the discharge straw cutting device for cutting the discharge straw after threshing treatment, a drive blade having a plurality of cutting blades supported on the drive shaft, a support blade having a plurality of support blades supported on the cutting shaft, a drive blade and a support blade In the combine is provided with a case for accommodating the, it is possible to quickly perform a task such as cleaning or inspection of the drive blade with a small number of people. The case 31 is provided with the case main body 31A with the rear part opened, and the rear part cover 31B which closes the rear part of the case main body 31A. The rear cover 31B is in a closed state that blocks the drive blade 34 from the rear and enables cutting processing by the discharge straw cutting device 10, and an open state in which the drive blade 34 is opened backward. It is configured to be changeable. Further, in the discharge straw cutting device for cutting the discharge straw after threshing treatment, a drive blade having a plurality of cutting blades supported on the drive shaft, a support blade having a plurality of support blades supported on the cutting shaft, a drive blade and a support blade In the combine is provided with a case
