Multi-optical axis photoelectronic sensor

This invention enables a worker, who performs a work for optical axis adjustment, to easily grasp whether adjustment for further increasing the light receiving quantity is possible. In a multi-optical axis photoelectronic sensor, a minimum value of the light receiving quantities obtained for every optical axis is detected every time a process of measuring, while lighting each light emitting element 10 by turns, the light receiving quantity of a light receiving element corresponding to a lighted light emitting element 10 is repeated for one cycle, and a peak value of the minimum light receiving quantities detected in the past is detected. A bar graph based on specific values of the most recent minimum light receiving quantity and the peak value, or a bar graph showing a proportion of the most recent minimum light receiving quantity with respect to the peak value is displayed using a plurality of indication lights 100, each arranged on the front surfaces of a light projector 1 and a light receiver 2. The bar graph changes according to the update of the peak value and the fluctuation in the value of the minimum light receiving quantity of every hour.