To enable cooling in summer and snow melting in winter via a heat pump of a natural refrigerant effectively using underground heat and also using air heat.

In this snow melting or cooling system using underground heat/air heat, the heat pump 30 operated for snow melting or cooling in winter or summer, respectively is used. At least in winter, by an underground heat exchanger 33 operated as an evaporator and a heating tower provided in the heat exchanger, while underground heat and air heat are collected, high temperature high pressure refrigerant gas is generated via a compressor 31 forming the heat pump, and heat for snow melting is generated by a brine heat exchanger 32 operated as a condenser. In summer, heat of the high temperature high pressure gas formed by the compressor is released by the underground heat exchanger operated as a condenser and the heating tower provided in the heat exchanger, cold for cooling is generated by the brine heat exchanger operated as an evaporator.