PROBLEM TO BE SOLVED: To provide a method for discriminating a safe state of a bather and a safety device 1 by which safety of a bather 5 is improved by discriminating a safety state regardless of the posture or position of the bather 5 in a bathroom and also by which the bather 5 is not bothered by malfunction.SOLUTION: A distance d to the bather 5 is successively measured by a plurality of distance measuring mechanisms 2 which are installed in a bathroom. The amount of change &Dgrd per prescribed time t0 of the distance d obtained by the distance measuring mechanisms 2 is calculated by each distance measuring mechanism 2. If even one of the plurality of calculated amounts of change &Dgrd exceeds a prescribed range &Dgrd0, it is discriminated as a safe state. If all of the plurality of calculated amounts of change &Dgrd are within the prescribed range &Dgrd0, it is discriminated as an abnormal state, with a warning issued.SELECTED DRAWING: Figure 2
