To provide a compact and light ball valve suited to handle a fluid, especially a cryogenic fluid, and to provide a connector using the same and a cryogenic fluid supplying system.

The cryogenic fluid supplying system 1 is structured of a mouth piece of a hydrogen tank and the connector 6 as a connector to be connected to a liquid hydrogen supplying nozzle of a hydrogen supplying station. The connector 6 has a male member 7 and a female member 8 detachably connected to each other. The male member 7 and the female member 8 are respectively provided with the ball valve 9 for controlling flow of the fluid in a connection end in each of the connection ends thereof. The ball valve 9 has a housing 21 formed with a plurality of flow passages 22 inside thereof, and a valve element 23 provided on the flow passages 22 to partition the flow passages. The housing 21 is provided with a large-diameter liquid hydrogen flow passage 22a and a small-diameter hydrogen gas flow passage 22b in parallel with each other. The valve element 23 is provided with through holes 24 corresponding to each of the flow passages 22.