To provide a structure for placing the flexible pipes of a swing type working machine, suited for miniaturizing a main body while providing good maintainability and visibility and preventing oil fouling.

A swing bracket 6 is connected by a vertical pin to a base 2 having a hydraulic source 3, and a swing hydraulic cylinder 8 is suspended between the base 2 and the side face 6s of the swing bracket 6. A working machine 4 having a working-machine hydraulic actuator is provided on the swing bracket 6, and a plurality of flexible pipes P (P1, P2) to be placed between the hydraulic source 3 and the working-machine hydraulic actuator of the swing type working machine 4 are placed on the side of the swing bracket 6 where the swing hydraulic cylinder 8 is placed. In that case, a first support member 10 into which the flexible pipes P combined are loosely fitted is provided on the side face 6s of the swing bracket 6, and a clearance for a curve is provided in the part of each flexible pipe P situated within an area extending from the base 2 to the first support member 10, this part being placed between the swing bracket 6 and the swing hydraulic cylinder 8.