An air conditioning device has a blower, a compressor, a radiator, a decompressor, a heat absorber, and a controller. The compressor compresses and discharges a refrigerant. The radiator dissipates a heat of the refrigerant to the air thereby heating the air. The decompressor decompresses the refrigerant after the heat of the refrigerant is dissipated in the radiator. The refrigerant decompressed in the decompressor absorbs heat from outside air in the heat absorber. The controller determines whether the heat absorber is in a frosted state in which a frost is formed on the heat absorber or whether the heat absorber is in an estimated frosted state in which a frost is possibly formed on the heat absorber. The controller performs a frost delay control to delay a formation of the frost when the controller determines that the heat absorber is in the frosted state or the estimated frosted state.