There is disclosed a controlling method for a refrigerator comprising: a first defrosting step of performing defrosting for an evaporator, the first defrosting step which ends when the temperature of the evaporator reaches a first temperature; a pressure difference sensing step of measuring a difference between the pressure in a first through-hole arranged between an inlet hole for drawing air from a storage compartment and the evaporator and the pressure in a second through-hole arranged between an outlet hole for discharging air towards the storage compartment and the evaporator by using one differential pressure sensor; and a second defrosting step of performing additional defrosting for the evaporator when the measured pressure difference is a preset pressure or more.