A multi-optical axis photoelectric sensor is describes having a first indicating portion disposed at each of the light emitting and receiving units comprising a plurality of first indicating elements being in the same row of each of the light emitting and receiving elements with no-interference to each of the light emitting and receiving elements, a second indicating portion disposed at one of the light emitting and receiving units and comprising a plurality of second indicating elements being out of the same row of one of the light emitting and receiving elements of the units having the second indicator portion with no-interference to one of the light emitting and receiving elements of the units having the second indicator portion and an indicating control portion for turning on the plurality of the first indicating elements of the first indicating portion to show the first and second rows of the units when the binary signal indicating the first status is outputted by the status output circuit and indicating a result of the diagnosis based on the diagnosis device with a predetermined turn-on pattern of the plurality of the second indicating elements of the second indicating portion when the malfunction is diagnosed by the diagnosis device.
Multi-optical axis photoelectric sensor