A refrigerating cycle apparatus, comprising: a refrigerant, a first circuit configured by a compressor that compresses said refrigerant; a radiator that radiates and cools said refrigerant discharged from said compressor; an ejector that decompresses and expands said refrigerant output from said radiator and converts an expansion energy to a pressure energy to increase a suction pressure of said compressor; and a gas-liquid separator that separates said refrigerant output from said ejector into a gas refrigerant and a liquid refrigerant, being circularly connected in order by piping, a second circuit configured such that between a liquid refrigerant outlet of said gas-liquid separator and a suction section of said ejector is connected by piping via a first throttle device which is an electronic expansion valve that decompresses said liquid refrigerant output from said liquid refrigerant outlet and an evaporator that evaporates said liquid refrigerant output from said first throttle device, and a second throttle device which is an electronic expansion valve that is provided on a piping path between the outlet of said radiator and the outlet of said first throttle device, characterized in that said refrigerating cycle apparatus further comprises an opening and closing valve provided on the piping path between the suction section of said ejector and the outlet of said ejector, said opening and closing valve being a check valve, wherein said refrigerant is HFO1234yf or a zeotropic refrigerant mixture having the global warming potential, GWP of less than 500, said refrigerating cycle apparatus is configured to operate in a bypass cycle operation or in an ejector cycle operation, in the bypass cycle operation, said refrigerating cycle apparatus is configured to fully close said first throttle device, to set said check valve in an open state and to set said second throttle device to decompress said liquid refrigerant, and no pressure recovery operation of said refrigerant is performed by said ejector, and in the ejector cycle operation, said refrigerating cycle apparatus is configured to fully closed said second throttle device, to set said check valve in a closed state and to set said first throttle device to decompress said liquid refrigerant, and pressure recovery operation of said refrigerant is performed by said ejector, and said refrigerating cycle apparatus is configured to fully close said first throttle to perform said bypass cycle operation when a throttle amount of said ejector becomes smaller than a first predetermined amount or larger than a second predetermined amount that is larger than the first predetermined amount, or when said ejector is blocked. a refrigerant, a first circuit configured by a compressor that compresses said refrigerant; a radiator that radiates and cools said refrigerant discharged from said compressor; an ejector that decompresses and expands said refrigerant output from said radiator and converts an expansion energy to a pressure energy to increase a suction pressure of said compressor; and a gas-liquid separator that separates said refrigerant output from said ejector into a gas refrigerant and a liquid refrigerant, being circularly connected in order by piping, a second circuit configured such that between a liquid refrigerant outlet of said gas-liquid separator and a suction section of said ejector is connected by piping via a first throttle device which is an electronic expansion valve that decompresses said liquid refrigerant output from said liquid refrigerant outlet and an evaporator that evaporates said liquid refrigerant output from said first throttle device, and a second throttle device which is an electronic expansion valve that is provided on a piping path between the outlet of said radiator and the outlet of said first throttle device, characterized in that said refrigerating cycle apparatus further comprises an opening and closing valve provided on the piping path between the suction section of said ejector and the outlet of said ejector, said opening and closing valve being a check valve, wherein said refrigerant is HFO1234yf or a zeotropic refrigerant mixture having the global warming potential, GWP of less than 500, said refrigerating cycle apparatus is configured to operate in a bypass cycle operation or in an ejector cycle operation, in the bypass cycle operation, said refrigerating cycle apparatus is configured to fully close said first throttle device, to set said check valve in an open state and to set said second throttle device to decompress said liquid refrigerant, and no pressure recovery operation of said refrigerant is performed by said ejector, and in the ejector cycle operation, said refrigerating cycle apparatus is configured to fully closed said second throttle device, to set said check valve in a closed state and to set said first throttle device to decompress said liquid refrigerant, and pressure recovery operation of said refrigerant is performed by said ejector, and said refrigerating cycle apparatus is configured to fully close said first throttle to perform said bypass cycle operation when a throttle amount of said ejector becomes smaller than a first predetermined amount or larger than a second predetermined amount that is larger than the first predetermined amount, or when said ejector is blocked.