A refrigerator with heat exchanger optimally configured to conserve electricity and improve a food storing capability at its best state. The refrigerator includes: a freezing room connected from an evaporator through a circulating passage, the freezing room having the circulating passage which circulates an air cooled by the evaporator; a storage room connected to the freezing room, in which a temperature of the storage room is set higher than that of the freezing room; a flow-in passage connected to the storage room where the air cooled by the evaporator flows into the storage room; a flow-out passage connected from the storage room where a chilled air flows out of the storage room; and a heat exchanger for exchanging heat between the cooled air flowing through the circulating passage and the chilled air flowing through the flow-out passage, so that the temperature inside the storage room is evenly and smoothly stable.