A fatigue degree input unit 101 inputs a fatigue degree of a user through use of a processing device 191, and writes an input value of the fatigue degree into a storage device 192. A recommended duration calculation unit 102 reads the input value of the fatigue degree written by the fatigue degree input unit 101 from the storage device 192. In accordance with the input value of the fatigue degree read from the storage device 192, the recommended duration calculation unit 102 calculates a bath duration to be recommended to the user, as a recommended duration, through use of the processing device 191. A recommended duration informing unit 103 informs the user of the recommended duration calculated by the recommended duration calculation unit 102, through an output device 194.
