An engine (10) electronically controlled by a control device (33), a hydraulic motor (24) for traveling which is driven by a pressurized oil delivered from a hydraulic pump (13), and a traveling speed switching member (29) which switches a traveling speed by the hydraulic motor (24) at least in two stages of a low speed and a high speed. The control device (33) includes an output lowering determination unit for determining whether or not a fuel injection amount to be supplied to the engine (10) is limited and an engine output is in a lowered state and a low-speed control unit in which, when the engine (10) output is in a lowered state, a traveling speed is controlled to a low speed state kept lower than a high speed even if the traveling speed switching member (29) has been switched to the high speed side.