To provide an ice machine for securing growth without excess or insufficiency in ice making in an ice making chamber even if temperature correction of external air of ice-making completion temperature cannot be performed effectively.

When calculated external air temperature in a step 101 is abnormal, it is judged as "YES" in a step 110 and the external temperature is set as a fixed external air temperature value in a step 113. In a step 115, the ice-making completion temperature is corrected based on the fixed external air temperature value. It is regarded as ice-making completion at the ice-making chamber when ice-making temperature reaches the corrected ice-making completion temperature.