To realize a cleaning state without dust left without being sucked in a prescribed range where cleaning is completed by simple constitution in a self-traveling cleaner.

The self-traveling cleaner 1 is provided with obstacle detection sensors 2a and 2b, internal map information and left and right drive wheels 32, etc., and performs cleaning by sucking the dust on a floor surface by a main nozzle 44 while autonomously traveling. The intake route of a sub nozzle 50 arranged at the rear part of the main nozzle 44 and the rear part of a power brush 41 in a traveling direction Z is from a dust box 43 to the rear part near the left and right ends of the main nozzle 44 and a sub nozzle opening is opened toward the floor surface F. A dust sensor 5 composed of an optical sensor is provided in the intake route of the sub nozzle 50, and the dust left without being sucked by the main nozzle 44 is detected. When the dust sensor 5 detects the dust with prescribed frequency, a cleaner main body is returned to an area where it is judged that the dust is left without being sucked, and the dust is sucked again by the main nozzle 44.