A branching tool (20) serving as a check valve incorporated in a cleaner device includes: a main unit (26) provided with an inflow channel (22) and a first outflow channel (24a); a sealing member (30) that allows a flow of cleaning fluid from the inflow channel (22) to the first outflow channel (24a) when the cleaner device is in operation and that is formed to seal a backflow of the cleaning fluid from the first outflow channel (24a) to the inflow channel (22) when the cleaner device is not in operation; and a lid member (28) that is combined with the main unit (26) so as to form a housing chamber (34) for the sealing member (30). The lid member (28) has a communication hole (40) that allows the housing chamber (34) to communicate with the outside. The lid member (28) or the main unit (26) is provided with a water receiving recess (42) arranged around the communication hole (40).