An electronic device includes a touch screen display, an input/output interface, a communication circuit, a memory, and a processor, and the processor modifies screen configuration information associated with at least a part of a resolution, a density, and an orientation of a screen output by the electronic device if the electronic device is connected to the external display device through the input/output interface, determines whether a target application to be displayed on the external display device supports resizing of a window that displays an execution screen of the target application, configures a first type of window which is resizable if the target application supports the resizing, configures a second type of window with a fixed size if the target application does not support the resizing, and displays the first type of window or the second type of window on the external display device.