Elements of power and operation systems, such as an engine and a transmission case, are efficiently arranged to effectively utilize the space of a traveling machine body. A traveling machine body (2) is provided with a side frame (12), the rear section of which is a tilted section (12a). An engine (21) is disposed in a tilted position below the tilted section (12a) of the side frame (12). A fuel tank (27) is disposed above the engine (21), and a seat (5) is disposed above the fuel tank (27). The engine (21) projects from the rear of the seat (5). A transmission case (22) is provided in front of the engine (21), and a maneuvering mechanism section (8) is located in front of the transmission case (22). The space below the side frame (12) is efficiently utilized, and power system elements are arranged in a balanced manner.
