A filter element is formed from a filter material configured to capture a foreign substance in fuel. A lower case is attachable to and detachable from a bottom portion of a housing in a movable direction. The housing and the lower case are configured to accommodate the filter element. The filter element defines a passage extending through the filter element in the movable direction. The passage is configured to accommodate the component. The component is configured to be attached to and detached from the housing together with the lower case when the lower case is attached to and detached from the housing.