To provide a refrigerant circuit comprising a function for suppressing excess expansion phenomenon or insufficient expansion phenomenon of a refrigerant in an expander, and comprising a multi-directional valve capable of simplifying a piping system and a control system.

The multi-directional valve 5 composed of a casing and a slidable valve element, and comprising eight ports, a throttle function and a bypass passage, is connected with the refrigerant circuit composed of a compressor 1, an outdoor heat exchanger 2, the expander 3 and an indoor heat exchanger 4, thus the piping system and the control system of the refrigerant circuit performing a heating/cooling operation can be simplified. Further the throttle function copes with insufficient expansion phenomenon when it occurs in the expander, and a circulation flow rate of the refrigerant circuit can be adjusted by using the bypass function.