To grasp a light-receiving state of disturbance light more in details than before in a multi-optical-axis photoelectric sensor comprising a plurality of light-receiving elements.

A processing circuit 26 sets a plurality of flood elements 11 into a non-flooding state through a processing circuit 16 and receives a signal S1 corresponding to light reception of disturbance light from each of a plurality of light-receiving elements 21. The processing circuit 26 generates light reception information (data DT) indicating a light-receiving state of the disturbance light for each of photodetectors of a prescribed number in the plurality of light-receiving elements 21. A communication circuit 27 transmits the data DT to the outside. A personal computer 5 displays the data DT received through a communication unit 4. In a sensor SNS, the quantity of light received for each optical axis, for example, is displayed by the personal computer 5. A worker thereby grasps the light-receiving state of the disturbance light more in details than before.