A cooking device is provided. The cooking device may include a cavity forming a space in which food may be received for cooking, a grill heater provided at one side of the cavity and having a plurality of heaters to heat the food, a food sensing device provided in the cavity to acquire information related to a size of the food received in the cavity, and a main controller to estimate the size of the food using information sensed by the food sensing device. The main controller may then operate a part or all of the plurality of heaters according to the estimated size of the food to perform a grill cooking operation.
