To provide a check valve wherein a holding part can reliably hold a valve member during closing the valve when the valve member is seated on an annular valve seat.

The check valve includes a valve casing consisting of an inlet side member 1 and an outlet side member 2 to form an inlet 4, a valve chest 3 and an outlet 5, the annular valve seat 6 provided between the inlet 4 and the valve chest 3, the valve member 7 arranged in the valve chest 3 for opening/closing the annular valve seat 6, the holding part 13 provided on the annular valve seat 6 for holding the valve member 7 during closing the valve when the valve member 7 is seated on the annular valve seat 6, the holding part 13 being formed separately from the annular valve seat 6, and a coil spring 16 for moving the holding part 13 forward to the side of the valve member 7. The holding part 13 is moved backward so that the valve member 7 is seated on the annular valve seat 6 to close the valve. Thereby, the holding part 13 can reliably hold the valve member 7 during closing the valve when the valve member 7 is seated on the annular valve seat 6.