The present invention provides an information processing device that, when the height of a reference plane of a bed is being set on a screen using a setting unit, clearly indicates, on a captured image, a region that is located at the height of the reference plane, based on depth information that is included in the captured image. It thereby becomes possible to readily set the reference plane of the bed, which serves as a reference for behavior of a person being watched over. Thereafter, the information processing device detects the behavior of the person being watched over, by determining whether the positional relationship between the reference plane of the bed and the person being watched over satisfies a predetermined condition.
