A multi-optical axis photoelectric sensor, comprising: an emitter unit including a plurality of emitter elements that are aligned linearly; a receiver unit including a plurality of receiver elements that are arranged to face the respective emitter elements; a detection processing unit (16, 26) configured to determine, in a detection area including a plurality of optical axes formed between the plurality of emitter elements and the plurality of receiver elements, whether each of the optical axes is in an interrupted state after optical axis selection corresponding to one scan, and output a detection signal based on a result of the determination; and a signal reception unit configured to receive a first signal immediately before an object that is movable within the detection area enters the detection area, wherein the detection processing unit (16, 26) is configured to perform, when at least one of the plurality of optical axes is constantly interrupted by the object, floating blanking of outputting the detection signal upon determining that the number of optical axes in an interrupted state is greater than a preset maximum optical axis number, and blanking monitoring of outputting the detection signal upon determining that the number of optical axes in an interrupted state is smaller than a preset minimum optical axis number, and the detection processing unit (16, 26) activates the floating blanking and the blanking monitoring based on the first signal received by the signal reception unit, the detection processing unit (16, 26) being configured to activate the floating blanking when receiving the first signal, characterized in that the signal reception unit is further configured to receive a second signal immediately before the object moves out of the detection area, wherein the detection processing unit (16, 26) activates the blanking monitoring when determining that the number of optical axes in an interrupted state is not less than the minimum optical axis number after the floating blanking is activated, deactivates the blanking monitoring after receiving the second signal, and further deactivates the floating blanking when determining that all the optical axes are in a light-entering state after receiving the second signal. an emitter unit including a plurality of emitter elements that are aligned linearly; a receiver unit including a plurality of receiver elements that are arranged to face the respective emitter elements; a detection processing unit (16, 26) configured to determine, in a detection area including a plurality of optical axes formed between the plurality of emitter elements and the plurality of receiver elements, whether each of the optical axes is in an interrupted state after optical axis selection corresponding to one scan, and output a detection signal based on a result of the determination; and a signal reception unit configured to receive a first signal immediately before an object that is movable within the detection area enters the detection area, wherein the detection processing unit (16, 26) is configured to perform, when at least one of the plurality of optical axes is constantly interrupted by the object, floating blanking of outputting the detection signal upon determining that the number of optical axes in an interrupted state is greater than a preset maximum optical axis number, and blanking monitoring of outputting the detection signal upon determining that the number of optical axes in an interrupted state is smaller than a preset minimum optical axis number, and the detection processing unit (16, 26) activates the floating blanking and the blanking monitoring based on the first signal received by the signal reception unit, the detection processing unit (16, 26) being configured to activate the floating blanking when receiving the first signal, characterized in that the signal reception unit is further configured to receive a second signal immediately before the object moves out of the detection area, wherein the detection processing unit (16, 26) activates the blanking monitoring when determining that the number of optical axes in an interrupted state is not less than the minimum optical axis number after the floating blanking is activated, deactivates the blanking monitoring after receiving the second signal, and further deactivates the floating blanking when determining that all the optical axes are in a light-entering state after receiving the second signal.