Electronic device and method to automatically control the brightness of electronic device

An electronic device according to an embodiment may include a display, a touch sensor, an illuminance sensor configured to generate illuminance information, a memory configured to store brightness data relating the ambient illuminance to brightness of the display, and a processor. The processor may be configured to identify the illuminance information from the illuminance sensor, configure the brightness of the display as first brightness, based on the illuminance information and the brightness data, change the brightness of the display to second brightness, based on a user input, acquire event information for an operation in which the brightness of the display is changed by the user input, reconfigure the brightness data stored in the memory, based on the event information, and determine the brightness of the display according to a brightness value mapped in the reconfigured brightness data to the illuminance information identified by the illuminance sensor.