This replacement necessity assessment apparatus for an absorbent member includes: a power generator which is configured to generate power as a result of contact with liquid absorbed in the absorbent member, and of which power generation amount changes in accordance with an amount of the liquid; a signal output unit configured to output a detection signal according to the power generation amount; and a processing unit configured to acquire a parameter regarding the amount of the liquid based on the detection signal, the processing unit configured to determine, based on the parameter, whether or not replacement of the absorbent member is necessary.