The present invention comprises: an absorbent core which is disposed in an absorbent article and absorbs excretions a pair of conductive members which are disposed in the absorbent article and have conductivity a detection part which detects the size of impedance between the conductive members and a control part which detects the presence or absence of excretion on the basis of a change pattern over time of the impedance detected by the detection part and determines whether the excretion is feces or urine on the basis of the percentage of impedance change with respect to time change after a prescribed time has passed after excretion is detected.