1. A status estimation apparatus comprising: a detector configured to detect a status change of at least one electrical device based on measurement data of a current flowing in a distribution line that supplies power to the at least one electrical device; a calculator configured to calculate a current waveform change and a power change that are associated with the status change based on the measurement data before and after the status change, upon detecting the status change; an estimator configured to estimate an electrical device of the at least one electrical device that caused the status change and a type of the status change based on the current waveform change; and a specifier configured to specify the electrical device that has caused the status change and the type of the status change based on the power change and an estimation result by the estimator, wherein the detector specifies a status change time when the status change has occurred, and the calculator extracts the current waveform change from a difference between current changes before and after the status change time.