A load control apparatus for use in a power supply system in which a power generator supplies electric power to a load device, and when electric power generated in the power generator is insufficient, a commercial power system supplies electric power to the load device, wherein the load control apparatus comprises: a controller configured to control an operation of a controlled device included in the load device on the basis of a measurement result by a measurement unit, the measurement unit being configured to measure consumed electric power in the load device and generated electric power by the power generator, wherein the controller includes: a prediction unit configured to predict surplus electric power generated in a target period from the present until a predetermined period of time elapses, the surplus electric power being a difference, as surplus electric power, between the generated electric power and the consumed electric power when the generated electric power is more than the consumed electric power; a determination unit; and an execution unit configured to control the controlled device to start a predetermined process, by transmitting a control signal to the controlled device, when the determination unit has already determined that the process can be executed; characterized in that the determination unit is configured to determine that the predetermined process can be executed by determining that electric power necessary for the predetermined process will continuously be secured from the start to the completion of the predetermined process in the target period including comparing the electric power and time necessary after the controlled device starts the predetermined process and before completing the predetermined process, with a prediction result by the prediction unit to determine propriety that the controlled device will execute the process with the predicted surplus electric power in the target period. a controller configured to control an operation of a controlled device included in the load device on the basis of a measurement result by a measurement unit, the measurement unit being configured to measure consumed electric power in the load device and generated electric power by the power generator, a prediction unit configured to predict surplus electric power generated in a target period from the present until a predetermined period of time elapses, the surplus electric power being a difference, as surplus electric power, between the generated electric power and the consumed electric power when the generated electric power is more than the consumed electric power; a determination unit; and an execution unit configured to control the controlled device to start a predetermined process, by transmitting a control signal to the controlled device, when the determination unit has already determined that the process can be executed; characterized in that the determination unit is configured to determine that the predetermined process can be executed by determining that electric power necessary for the predetermined process will continuously be secured from the start to the completion of the predetermined process in the target period including comparing the electric power and time necessary after the controlled device starts the predetermined process and before completing the predetermined process, with a prediction result by the prediction unit to determine propriety that the controlled device will execute the process with the predicted surplus electric power in the target period.