The judgment below is reversed and the case is remanded to Seoul High Court.

We examine the grounds of appeal ex officio prior to examining it.

1. If there exists a seizure and collection order against the claim, only the collection creditor may institute a lawsuit for performance against the garnishee, and the debtor shall lose the standing to institute a lawsuit for performance against the seized claim;

This is a matter to be examined ex officio and determined by the court, even if the party's assertion was not made, and if circumstances, such as the standing to sue, occur after the conclusion of the fact-finding proceedings, it should be considered in

(2) According to the reasoning of the lower judgment and the record, the Plaintiff (Counterclaim Plaintiff; hereinafter “Plaintiff”)’s claim against the Defendant (hereinafter “Defendant”) seeking payment of unpaid construction payment, etc. after being awarded a contract for new construction of the building of this case from the Defendant, and L received a collection order from the Seoul Central District Court Decision 2017Ma115302, Oct. 26, 2017, 201, with respect to the claim against the Defendant under the substantive law, which is the subject matter of the lawsuit, where the third party obligor indicated the amount to be paid to the obligor as the seized claim (see, e.g., Supreme Court Decision 2010Da4044, Apr. 28, 2011).

3. Examining the foregoing legal principles in light of the legal principles as seen earlier, the instant lawsuit seeking payment of the unpaid construction cost, etc. by serving the Defendant, who is the garnishee, may be filed only L, and the Plaintiff shall lose its standing to file the lawsuit.

Therefore, the lower court.