A controller mounted on a small-sized hydraulic excavator includes an engine restart section that restarts an engine when a horn switch operation determining section determines that a horn switch is operated and a gate lock lever position determining section determines that a gate lock lever is at a lock position in a case where a restart standby time determining section determines that restart standby time does not yet elapse after the engine is automatically stopped by an idling stop function, and a power supply stopping section that stops an electric power supply of a vehicle body when the restart standby time determining section determines that the restart standby time has elapsed.