To simplify the structure by controlling a valve element to the 1st position of allowing first and second outflow and inflow ports to communicate each other and closing a bypass opening, the 2nd position of allowing second and third outflow and inflow ports to communicate each other and closing the bypass opening and the 3rd position of allowing the second and third outflow and inflow ports to communicate each other and opening the bypass opening.

In cooling, a communicating groove part 52 on the reverse side of a valve element 51 allows outflow and inflow ports 41, 42, so that the coolant from a compressor is carried from a passage 45 to an outdoor heat exchanger through an opening part 54 and an outflow and inflow port 43, and a bypass opening 44 is laid in the closed state by a lid part 53. In heating, the valve element 51 is moved to the right to allow the outflow and inflow ports 42, 43 to communicate each other by the groove part 52, so that the coolant from the compressor is carried to an indoor heat exchanger through an inflow port 45 and the outflow port 41, and the bypass opening 44 is laid in the closed state by the lid part 52. In defrosting, the valve element 51 is moved further to the right to allow the outflow and inflow ports 42, 43 to communicate each other by the groove part 52, so that the coolant from the compressor. is carried to the indoor heat exchanger through the inflow port 45 and outflow port 41, and the bypass opening 44 is laid in open state by an opening part 54. Thus, the structure can be simplified.