To provide a structure safely and rapidly performing operation and improving the operating efficiency without trouble in a machine body at all even if a lifting part provided in a traveling transmission site is utilized during disassembling or assembling when maintenance of a combine harvester is carried out.

The combine harvester is equipped with a pretreatment part (2) at the front of the traveling machine body (1), the traveling transmission (10) under the pretreatment part (2) and a driving operation part (3) in a lateral part of the pretreatment part (2). The combine harvester is provided with the lifting part (13) on the traveling transmission (10) and is composed so as to retract the driving operation part (3) from a part just above the lifting part (13) of the traveling transmission (10) so that the upper part of the lifting part (13) is opened in the opened state of the front and upper part of the traveling transmission (10) by removing the pretreatment part (2) or rotating the pretreatment part (2) to the left with a fulcrum on the left side as the center.