The present invention aims to provide a bodily fluid trapping unit assuring that bodily fluid can be guided into a receptacle without anxiety of flowing back and a wearing article including such bodily fluid trapping unit. A receptacle 10 of a bodily fluid trapping unit 1 is defined by first and second sheets 12, 13 bonded together along respective peripheral edges thereof so as to form a bag. The first sheet 12 is formed with openings 11 extending therethrough in its thickness direction. Backflow preventing means 20 includes a flat valve disc 30 provided on the side of the first sheet 12 facing the receptacle 10, a sheet-like support base 40 serving to prevent the valve disc 30 from falling into the receptacle 10 and a spacer 50 interposed between the first sheet 12 and the support base 40. A peripheral edge of the valve discs upper surface 31 is adapted to come in water-tight contact with the associated valve seat 14 formed on the side of the openings peripheral edge facing the receptacle 10. Between the first sheet 12 and the support base 40, a space is defined by a spacers opening 53 so that the valve disc 30 may be movably supported in the thickness direction of the spacer 50.
