This heater control device keeps down costs and quickly energizes multiple PTC elements, and is provided with: a current calculation unit (20) which, on the basis of a first current value flowing through a first PTC element of a first PTC heater currently in a energized state and a second current value estimated to be flowing through a second PTC element of a second, new PTC heater to be subsequently placed in the energized state, calculates a third current value; and a switch control unit (21) which maintains the second PTC element of the second PTC heater in an unenergized state as long as the third current value calculated by the current calculation unit (20) is determined to be less than a prescribed maximum allowable current value, and places the second PTC element of the second PTC heater into an energized state when said third current value is less than the prescribed maximum allowable current value.