A heating water distributor is a device that distributes hot water from a boiler to places where heating is needed (room, living room, kitchen, etc.). Company B, which manufactures and installs the heating water distributor, filed an infringement lawsuit against Company S for infringing the patent of Company B, and the court found the infringement at the first instance. After that, AIP, on behalf of Company S, appealed to the decision of the first instance, and requested a trial to confirm scope of rights. The court decided that Company S' heating water distributor did not belong to the scope of rights because the method of distributing heating water was different from Company B's patent. Company B's infringement lawsuit was dismissed for the same reason in the appeal trial. In particular, this case is meaningful in that there was a dispute whether there is an interest in requesting a trial for filing a request for a trial to confirm scope of rights after an infringement lawsuit has been initiated, but the Supreme Court has decided that there is an interest in requesting a trial even in such cases.