To solve a problem that rising of crude oil costs caused by oil prices soaring of overall society, puts pressure on profit, though a fan forced heater, a heavy oil heater, a warm water heater and the like are used in protected horticulture cultivation in a green house, and these apparatuses use crude oil as power sources.

This non-defrost heat pump device for protected horticulture cultivation includes an indoor unit disposed inside of the green house for protected horticulture cultivation, a refrigerant pipe connected with the indoor unit to allow a refrigerant to flow in and out, a non-defrost heat pump outdoor unit of which a refrigerant pipe is connected to the indoor unit, a heat exchanger connected with the non-defrost heat pump outdoor unit for absorbing water cold heat source (latent heat) of ground heat or groundwater, and a blower disposed neat the heat exchanger.