A refrigerator includes a first passage including a cold storage zone capillary tube and a cold storage zone evaporator, the latter two being connected in series to each other, a second passage including a freezing zone capillary tube and a freezing zone evaporator, the latter two being connected in series to each other, a switching valve causing the refrigerant condensed by the condenser to flow selectively through any one of the first passage, the second passage and both the first and second passages, a variable speed, cold storage zone fan circulating air in the cold storage zone while the air is in contact with the cold storage zone evaporator, a variable speed, freezing zone fan circulating air in the freezing zone while the air is in contact with the freezing are evaporator, and a control device switching the switching valve upon power supply to the refrigerator so that the refrigerant flows simultaneously through both the first and second passages, starting the compressor, starting the cold storage zone fan so that the fan is driven at a high speed, starting the freezing zone fan so that the fan is driven at a lower speed than the cold storage zone fan, and starting the heat-dissipating fan so that an operation in which atmospheres in both the cold storage and freezing zones are simultaneously cooled is continued until a temperature or temperatures in the cold storage and/or freezing storage zone decreases to a value or values smaller than a predetermined value or values, respectively or until a predetermined period of time elapses after the power supply to the refrigerator, the control means thereafter executing a normal operation mode.