A processing apparatus predicts a first demand amount and a first supply amount in the plan period, selects a candidate group, which is a candidate of a target of a load control, from among the plurality of devices, sends confirmation information that indicates a confirmation of the load control to a communication destination corresponding to the candidate group, upon receiving refusal information that indicates that the load control is refused, excludes the device corresponding to the refusal information from the candidate group, after the selection of the candidate group, receives second demand information and second supply information, predicts a second demand amount and a second supply amount in the plan period, selects a target group, which is a target of the load control, from among the candidate group, and sends a command to the control apparatus corresponding to the target group.