[Technical Problem] Provided is a check valve element enabling efficient supply of fluid while suppressing the occurrence of chattering. [Solution to Problem] The check valve element (48) is provided to be displaceable upstream and downstream in a downstream flow path (42) extending downstream from a valve seat (36) having an opening for introducing a fluid and is pressed against the valve seat by a pre-closing urging force applied thereto toward an upstream side. The check valve element has an arresting portion (48d) provided on an outer peripheral surface (48b) thereof, a sliding resistance imparting member support portion (48b-1) supporting a sliding resistance imparting member (52) such that the sliding resistance imparting member slides along the wall of the downstream flow path when the check valve element is displaced upstream and downstream, and an urging member support portion (48b-2) supporting an urging member (50b) urged upstream so that the urging member urges the sliding resistance imparting member upstream, thereby causing the sliding resistance imparting member to increase in outer diameter while being arrested by the arresting portion (48d).