An electronic device comprising: a display ; a touch sensor configured to receive a user's touch input and generate touch information; an illuminance sensor configured to detect ambient illuminance and generate illuminance information; a memory configured to store brightness data which maps an ambient illuminance value and a brightness value of the display ; and a processor operatively connected to the display , the illuminance sensor , the touch sensor , and the memory , wherein the processor is configured to: identify illuminance information from the illuminance sensor , configure the brightness of the display as a first brightness, based on the illuminance information and the brightness data, change the brightness of the display to a second brightness, based on a user input, acquire event information for an operation in which the brightness of the display is changed, wherein the event information includes illuminance information identified when the user input is detected and the second brightness, reconfigure the brightness data stored in the memory , based on the event information, and determine, in an automatic brightness mode, the brightness of the display according to a brightness value in the reconfigured brightness data mapped to an illuminance value identified by the illuminance sensor , when the reconfigured brightness data is stored in the memory . a display ; a touch sensor configured to receive a user's touch input and generate touch information; an illuminance sensor configured to detect ambient illuminance and generate illuminance information; a memory configured to store brightness data which maps an ambient illuminance value and a brightness value of the display ; and a processor operatively connected to the display , the illuminance sensor , the touch sensor , and the memory , wherein the processor is configured to: identify illuminance information from the illuminance sensor , configure the brightness of the display as a first brightness, based on the illuminance information and the brightness data, change the brightness of the display to a second brightness, based on a user input, acquire event information for an operation in which the brightness of the display is changed, wherein the event information includes illuminance information identified when the user input is detected and the second brightness, reconfigure the brightness data stored in the memory , based on the event information, and determine, in an automatic brightness mode, the brightness of the display according to a brightness value in the reconfigured brightness data mapped to an illuminance value identified by the illuminance sensor , when the reconfigured brightness data is stored in the memory . identify illuminance information from the illuminance sensor , configure the brightness of the display as a first brightness, based on the illuminance information and the brightness data, change the brightness of the display to a second brightness, based on a user input, acquire event information for an operation in which the brightness of the display is changed, wherein the event information includes illuminance information identified when the user input is detected and the second brightness, reconfigure the brightness data stored in the memory , based on the event information, and determine, in an automatic brightness mode, the brightness of the display according to a brightness value in the reconfigured brightness data mapped to an illuminance value identified by the illuminance sensor , when the reconfigured brightness data is stored in the memory . <EOS>