An air conditioner which comprises: a temperature sensor; and a processor that obtains, based on receiving a turn-on command for the air conditioner, a first temperature value sensed through the temperature sensor; based on a threshold time elapsing subsequent to the receiving of the turn-on command, obtains a second temperature value sensed through the temperature sensor; and provides notification information related to an environment in which the air conditioner is installed, on the basis of the first temperature value and the second temperature value.