A method and a device for controlling a supply of a developer are provided. An amount of the developer is sensed during warm-up and a determination is made as to whether the sensed amount is equal to or less than a predetermined threshold during warm-up. The developer is supplied during warm-up and the amount of the developer is sensed when a determination is made that the sensed amount is equal to or less than the threshold. The supplying of the developer is stopped during warm-up when a determination is made that the sensed amount is greater than the threshold. Also, the method may include determining whether an amount of the developer is greater than a predetermined threshold by analyzing a given flag and stopping the supply of the developer and forming an image using the developer, when it is determined that the amount of the developer is greater than the threshold. In addition, the method may include determining whether an amount of the developer is greater than a predetermined threshold by analyzing a given flag after completing a printing job and stopping the supply of the developer when it is determined that the amount of the developer is greater than the threshold after completing a printing job.