To provide a check valve device having the high degree of freedom in size selection, and a water supply facility equipped with such a check valve device.

The check valve device G1 prevents back flow of hot and cold water being seated on a valve seat part 11 having a communicating hole 18 allowing communication between a primary side passage part N1 and a secondary side passage part N2 of the water supply facility S. A nonreturn packing 41 is clamped by a spring guide part 30 slidably mounted to a valve stem part 50 through a spring 55, and a packing guide part 20 having a pressure relief hole 21c. A safety packing 45 is interposed between the valve stem part 50 and the packing guide part 20. The nonreturn packing 41 and the safety packing 45 are relatively displaceable in the axial direction of the valve stem part 55.