In order to estimate behavior of a person at home from a feature and a power consumption pattern of an electrical device, an on-demand power control system of the present invention includes initial human-induced probability value estimation means that estimates a state of the electrical device, and estimates an initial value of a human-induced probability of the electrical device based on the estimated state of the electrical device, human position estimation means for calling up the initial value of the human-induced probability of the electrical device and a likelihood map of this device from a memory, performing, for all samples, a process of referring to a sample human position selected from the likelihood map and calculating a weight of the device by multiplying a human position and the human-induced probability of the device, and estimating a probability of a human position at each time point until a final time; and human-induced probability re-estimation means for performing recalculation of the human-induced probability based on the human-induced probability and a human position probability, performing the recalculation of the human-induced probability until a value of the recalculation converges, and outputting the human-induced probability and the human position probability when the value converges.