A demand control device comprising: air-conditioning control means to perform low power operation control on a per-group basis when indoor units are grouped into a plurality of groups, by making a group to which one or more indoor units belong perform a low power operation, wherein in the low power operation the group of the one or more indoor units operates with low load by performing a suspending operation or an air blowing operation; estimation means to estimate, as reducible power of the group, power calculated from a power amount reduced when each group separately performs the low power operation for a predetermined measurement unit time in a predetermined measurement period from a start point of a demand time limit by calculating a difference between a power consumption during a normal action of the group and a power consumption during the low power operation of the group; prediction means to predict a power consumption amount at an end point of the demand time limit; and calculation means to calculate, when the power consumption amount predicted by the prediction means exceeds a target demand power amount previously set to the demand time limit, a power amount to be reduced in order not to exceed the target demand power amount as a target reduced power amount, distribute the target reduced power amount evenly to each group, and calculate, for each group, a low power operation time to reduce the target reduced power amount distributed for each group based on the reducible power, wherein the air-conditioning control means makes the group perform the low power operation for the low power operation time calculated for each group by the calculation means before the end point of the demand time limit after the predetermined measurement period passes. air-conditioning control means to perform low power operation control on a per-group basis when indoor units are grouped into a plurality of groups, by making a group to which one or more indoor units belong perform a low power operation, wherein in the low power operation the group of the one or more indoor units operates with low load by performing a suspending operation or an air blowing operation; estimation means to estimate, as reducible power of the group, power calculated from a power amount reduced when each group separately performs the low power operation for a predetermined measurement unit time in a predetermined measurement period from a start point of a demand time limit by calculating a difference between a power consumption during a normal action of the group and a power consumption during the low power operation of the group; prediction means to predict a power consumption amount at an end point of the demand time limit; and calculation means to calculate, when the power consumption amount predicted by the prediction means exceeds a target demand power amount previously set to the demand time limit, a power amount to be reduced in order not to exceed the target demand power amount as a target reduced power amount, distribute the target reduced power amount evenly to each group, and calculate, for each group, a low power operation time to reduce the target reduced power amount distributed for each group based on the reducible power, wherein the air-conditioning control means makes the group perform the low power operation for the low power operation time calculated for each group by the calculation means before the end point of the demand time limit after the predetermined measurement period passes.