The invention provides a multi-optical axis photoelectric sensor. For a manufacturing machine that moves in and out of a detection area of a multi-optical axis photoelectric sensor, floating blanking and blanking monitoring are activated without outputting a stop signal to stop the manufacturing machine every when the manufacturing machine moves out of the detection area. A detection processing unit performs, 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 activates or deactivates the floating blanking and the blanking monitoring based on the signals received by the signal reception unit.