A refrigerator comprising: a duct arranged to partition an inner space of a storage chamber body into a storage chamber (S) and an air flow channel (P), wherein the duct has an ejection hole defined therein; a roll-bond evaporator disposed in the air flow channel (P), wherein the roll-bond evaporator has a top and a bottom , a left end and a right end ; a blowing fan configured to draw air from the storage chamber (S) to blow the air into the air flow channel (P), wherein one of the top and bottom of the roll-bond evaporator is closer to the blowing fan than the other of the top and bottom of the roll-bond evaporator ; the refrigerator being characterised in that it further comprises: a defrost sensor configured to detect a temperature of the roll-bond evaporator , wherein the defrost sensor is closer to one of the top and bottom of the roll-bond evaporator than the other of the top and the bottom, wherein the defrost sensor is closer to one of the left end and the right end of the roll-bond evaporator than the other of the left end and the right end; and a controller configured to perform a multi-steps defrost of the roll-bond evaporator comprising sequentially a first defrost mode (S1), a storage chamber cooling mode (S2), and a second defrost mode (S3), wherein in the first defrost mode (S1), a compressor is in an off state and the blowing fan rotates, wherein in the storage chamber cooling mode (S2), the compressor is in an on state, and the blowing fan rotates, and wherein in the second defrost mode (S3), the compressor is in an off state and the blowing fan rotates. a duct arranged to partition an inner space of a storage chamber body into a storage chamber (S) and an air flow channel (P), wherein the duct has an ejection hole defined therein; a roll-bond evaporator disposed in the air flow channel (P), wherein the roll-bond evaporator has a top and a bottom , a left end and a right end ; a blowing fan configured to draw air from the storage chamber (S) to blow the air into the air flow channel (P), wherein one of the top and bottom of the roll-bond evaporator is closer to the blowing fan than the other of the top and bottom of the roll-bond evaporator ; the refrigerator being characterised in that it further comprises: a defrost sensor configured to detect a temperature of the roll-bond evaporator , wherein the defrost sensor is closer to one of the top and bottom of the roll-bond evaporator than the other of the top and the bottom, wherein the defrost sensor is closer to one of the left end and the right end of the roll-bond evaporator than the other of the left end and the right end; and a controller configured to perform a multi-steps defrost of the roll-bond evaporator comprising sequentially a first defrost mode (S1), a storage chamber cooling mode (S2), and a second defrost mode (S3), a defrost sensor configured to detect a temperature of the roll-bond evaporator , wherein the defrost sensor is closer to one of the top and bottom of the roll-bond evaporator than the other of the top and the bottom, wherein the defrost sensor is closer to one of the left end and the right end of the roll-bond evaporator than the other of the left end and the right end; and a controller configured to perform a multi-steps defrost of the roll-bond evaporator comprising sequentially a first defrost mode (S1), a storage chamber cooling mode (S2), and a second defrost mode (S3), wherein in the first defrost mode (S1), a compressor is in an off state and the blowing fan rotates, wherein in the storage chamber cooling mode (S2), the compressor is in an on state, and the blowing fan rotates, and wherein in the second defrost mode (S3), the compressor is in an off state and the blowing fan rotates. <EOS>