An oven having a cabinet and a cooktop disposed above the cabinet is provided. The cooktop includes a top frame located at a top surface of the cabinet, the top frame including at least one heater installation opening and at least two heater support brackets adjacent the installation opening, a top plate located on a top surface of the top frame, and a heater located in the installation opening, the heater including at least two heater support holders, each support holder being elastically coupled to a corresponding support bracket to movably support the heater.