A heat exchange system (1A to 1D) comprising: a first heat exchanger; a second heat exchanger; a compressor provided on a first path that is one of two paths connecting said first heat exchanger and said second heat exchanger, said compressor compressing a refrigerant; a switching valve which is provided on the first path to selectively connect the discharge side of the compressor to the first heat exchanger and the second heat exchanger, a variable throttle provided on a second path of the two paths connecting said first heat exchanger and said second heat exchanger, said second path being a path opposite to the path on which said compressor is provided; a further throttle provided on said second path; and a cooling element that is provided on said second path and that cools an object to be cooled, said cooling element being located between said variable throttle and said further throttle, characterised in that said further throttle is a fixed throttle, and the heat exchange system further comprises a check valve provided on a bypass passage that connects a first branch position (B1; B3) and a second branch position (B2; B4) in parallel with said fixed throttle, said first branch position being on a side of one end of said fixed throttle and said second branch position being on a side of the other end of said fixed throttle, wherein said check valve is provided to allow said refrigerant to flow from said first branch position (B1; B3) on the side of the both ends of said fixed throttle that is farther from said cooling element to said second branch position (B2; B4) on the side of the both ends of said fixed throttle that is closer to said cooling element. a first heat exchanger; a second heat exchanger; a compressor provided on a first path that is one of two paths connecting said first heat exchanger and said second heat exchanger, said compressor compressing a refrigerant; a switching valve which is provided on the first path to selectively connect the discharge side of the compressor to the first heat exchanger and the second heat exchanger, a variable throttle provided on a second path of the two paths connecting said first heat exchanger and said second heat exchanger, said second path being a path opposite to the path on which said compressor is provided; a further throttle provided on said second path; and a cooling element that is provided on said second path and that cools an object to be cooled, said cooling element being located between said variable throttle and said further throttle, characterised in that said further throttle is a fixed throttle, and the heat exchange system further comprises a check valve provided on a bypass passage that connects a first branch position (B1; B3) and a second branch position (B2; B4) in parallel with said fixed throttle, said first branch position being on a side of one end of said fixed throttle and said second branch position being on a side of the other end of said fixed throttle, wherein said check valve is provided to allow said refrigerant to flow from said first branch position (B1; B3) on the side of the both ends of said fixed throttle that is farther from said cooling element to said second branch position (B2; B4) on the side of the both ends of said fixed throttle that is closer to said cooling element.