If an inheritor has not submitted evidence proving that he was a qualified acceptor in the midst of the action brought by a creditor and a final and conclusive judgment without limitation of liability has been handed down in the action, whether or not the inheritor may start a new trial based on the fact that he has effected the qualified acceptance is closely linked to the discussion about whether or not the scope of liability is included to the object of the lawsuit. Under the Article 216 of the Civil Procedure Act, a final and conclusive judgment shall have the effect of res judicata in so far as the matters contained in the text thereof are concerned. In other words, the effect of res judicata is concerned with the object of the lawsuit, which is contained in the text of the judgment. In my opinion, the object of the lawsuit in an action for monetary debt is to decide on whether or not a defendant is obliged to pay the debt to the plaintiff, not on the scope of liability. The scope of liability, that is, which property of the defendant shall be subject to the execution power of the final and conclusive judgment is not related to the object of the lawsuit and it is true that the scope of liability eventually matters in the stage of compulsory execution, after the final and conclusive judgment has been handed down in a lawsuit. When a defendant makes a separate plea of qualified acceptance of inheritance, he does not intend to contest a right or claim alleged as a reason for the request by the plaintiff, rather the inheritor admits that he is obliged to pay the inheritee’s debt but claims that the performance shall be limited to the extent of the property to be acquired through the inheritance. Therefore, the principle of res judicata shall not be applied to the scope of the liability and the inheritor can start a new trial alleging limitation of liability against creditors in a compulsory execution procedure. And regarding the way of claiming limitaion of liability in a compulsory execution procedure, the Supreme Court has ruled that a debtor may raise objection making a plea of qualified acceptance of inheritance against claims which have become final and conclusive by a judgment by filing a lawsuit of demurrer against claims pursuant to the Article 44 of the Civil Execution Act. However, according to the Article, for the demurrer against claims, any grounds therefor shall be those which have arisen subsequently to a closure of pleadings, so if the inheritor could have claimed that he was a qualified acceptor before the closure of the pleadings, the same ground cannot be a ground for the demurrer against claims. So the lawsuit of demurrer against claims is not appropriate in this case. Therefore, in my opinion, the inheritor should claim limitation of liability by filing a lawsuit of demurrer by third party under Article 48 of Civil Procedure Act. In case of renunciation of inheritance, an inheritor cannot start a new trail based on the fact that he has effected renunciation of inheritance due to the doctrine of res judicata. However, in consideration of the demanding need to protect an inheritor, especially who is young and legally ignorant, the principle of estoppel should be widely applied to the specific cases.