A check valve comprising: a casing having a flow path formed therein and a valve seat formed at an intermediate portion of said flow path; a valving element disposed at the downstream side of the valve seat in said flow path, said valving element being movable in said flow path to selectively seat on and unseat from said valve seat at the upstream end thereof; an urging member that urges said valving element toward said valve seat; a substantially circular cylindrical valving element support (21 a) fixedly disposed, in particular centrally, in said flow path downstream of the valve seat, said valving element support having at the upstream end thereof a recess that movably receives said valving element; an intermediate flow path (68, 69, 70), in particular annular in section, formed between an outer periphery of said valving element support and an inner periphery of said casing, said intermediate flow path communicating between upstream and downstream sides of said flow path when said valving element unseats from said valve seat; wherein said intermediate flow path has a first portion being a narrow flow path portion extending over a predetermined range from said upstream end of said valving element support and being narrower in flow path area than a rest of said intermediate flow path; characterized in that a constantly existing communication between the recess and the downstream side of the flow path is given via a communicating passage that communicates between said recess and said narrow flow path portion, wherein said valving element has a top having an outer periphery that faces an inner periphery of a portion at the upstream side of said recess of said valving element support, and in that said communicating passage is formed between said inner periphery of the recess and the outer periphery of the top of said valving element. a casing having a flow path formed therein and a valve seat formed at an intermediate portion of said flow path; a valving element disposed at the downstream side of the valve seat in said flow path, said valving element being movable in said flow path to selectively seat on and unseat from said valve seat at the upstream end thereof; an urging member that urges said valving element toward said valve seat; a substantially circular cylindrical valving element support (21 a) fixedly disposed, in particular centrally, in said flow path downstream of the valve seat, said valving element support having at the upstream end thereof a recess that movably receives said valving element; an intermediate flow path (68, 69, 70), in particular annular in section, formed between an outer periphery of said valving element support and an inner periphery of said casing, said intermediate flow path communicating between upstream and downstream sides of said flow path when said valving element unseats from said valve seat; wherein said intermediate flow path has a first portion being a narrow flow path portion extending over a predetermined range from said upstream end of said valving element support and being narrower in flow path area than a rest of said intermediate flow path; characterized in that a constantly existing communication between the recess and the downstream side of the flow path is given via a communicating passage that communicates between said recess and said narrow flow path portion, wherein said valving element has a top having an outer periphery that faces an inner periphery of a portion at the upstream side of said recess of said valving element support, and in that said communicating passage is formed between said inner periphery of the recess and the outer periphery of the top of said valving element.