A heating cooker produces hot steam by boiling water in a cooking cavity thereof, and cooks food by use of the hot steam to prepare steamed food. The heating cooker has a cabinet to define a cooking cavity therein. A steaming vessel to contain food and water therein, is laid on a bottom wall of the cooking cavity. A heater is provided at the bottom wall of the cooking cavity to heat the bottom wall of the cooking cavity on which the steaming vessel is laid. Thus, the heater heats the water contained in the steaming vessel, so that the water is boiled to produce the hot steam.