To solve the difficulty in efficiently raising the temperature near crops in an energy-saving manner. In a frost and freezing preventing apparatus, a fan disposed at a high position blows air downward from a high place toward a low place and a fan disposed at a low position blows air in a substantially horizontal direction. A heater is provided in the farm field. The fan at the high position is operated only when the temperature in the high place, in which an inversion layer may be caused, is high. After that, if a temperature drop occurs near the crops, the heater is operated. Conversely, if the temperature in the high place, in which an inversion layer may be caused, is equal to or lower than the temperature near the crops, the fan at the high position is not operated and the heater and/or the fan at the low position is operated so that warm air is blown in a substantially horizontal direction. Thus, damage due to freezing and frost can be prevented.
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