To provide the subject working machine having no inconvenience in which a large amount of mud and waste straw are piled in an auxiliary raising case to cause increase in load of a raising chain and consequently deformation and damage occur by covering an exhaust port formed in the auxiliary raising case with a specific discharging cover.

In installing an auxiliary raising case 12 for raising stem and culm by forward projecting raising tines 15 at the front of a raising case for raising stem and culm by laterally projecting raising tines 15, a raising chain 16 to which the plural raising tines 15 pivotally attached is hung between a driving wheel and a driven wheel vertically built in the case 12. In a rising route of the chain 16, the raising tines 15 are raised and projected from the case 12. On the other hand, in the falling route, the raising tines 15 are lodged and housed in the case 12 to provide the objective working machine for reaping stem and culm 12. The auxiliary raising case 12 is provided with an exhaust port 12d facing the falling route of the chain 16 and the exhaust port 12d is covered from the outside with an openable and closable discharging cover 19 energized in the closing direction.