A refrigerator comprises a storage compartment configured to store food, a temperature detector configured to detect an internal temperature of the storage compartment, a cooler configured to supply cool air to the storage compartment, a microphone configured to receive a speech, a display configured to display information, at least one processor configured to be electrically connected to the temperature detector, the microphone, and the display; and a memory configured to be electrically connected to the at least one processor. The memory stores at least one instructions configured to, when a first speech including a food name is recognized via the microphone, allow the processor to display a food list, which comprises food information corresponding to the food name and an identification mark identifying the food information, on the display, and configured to, when a second speech referring to the identification mark is recognized via the microphone, allow the processor to display food purchase information corresponding to the identification mark, on the display.