An excretion detection device that includes a power supply unit having an electrode and an electrode configured by using materials having different ionization tendencies a solution retention unit configured to retain an electrolyte solution, a temperature sensor configured to detect the temperature information, and an active tag including a radio transmission unit configured to transmit the temperature information detected by the sensor to outside the excretion detection device. The electrode and the electrode are installed at a position where the electrodes can be in contact with the bodily waste and the electrolyte solution, and can also be in contact with the electrolyte solution before the excretion of the bodily waste.