1. The plaintiff's claim is dismissed.

2. The costs of lawsuit shall be borne by the Plaintiff.

1. The parties' assertion

A. The Defendant subcontracted to the Plaintiff on June 5, 2015, the construction work portion among the construction work of “Yanyang-si Underground Sewage Treatment Facility” that was contracted by the Korea Environment Corporation.

However, on March 25, 2015, the Defendant voluntarily terminated the said subcontract, and based on the subcontract guarantee certificate and the subcontract advance payment guarantee certificate issued by the construction mutual aid association and submitted by the Plaintiff to the Defendant, the Defendant filed a claim with the construction mutual aid association for the payment of KRW 372,98,000 and the advance payment deposit of KRW 355,30,000.

However, since the above termination of the contract by the defendant is invalid as it is unlawful and invalid, there is no obligation to return the contract deposit of KRW 372,988,00 to the defendant, and KRW 55,782,612 out of the advance payment of KRW 355,30,000 paid to the plaintiff is already returned to the defendant, and there is no obligation to return the advance payment deposit of KRW 55,782,612 to the defendant.

B. The Plaintiff filed a suit against the Defendant that the Defendant did not have any obligation to return KRW 372,98,00,00 for the above contract deposit against the Defendant, and the advance payment deposit amount of KRW 355,30,000 (hereinafter “pre-appeal”), and the said suit became final and conclusive against the Plaintiff.

The plaintiff sought confirmation in the lawsuit of this case that there is no obligation to return KRW 55,782,612 among the advance payment deposit, and only reduced part of the lawsuit, and since the subject matter of the lawsuit of this case is the same as that of the previous lawsuit, the plaintiff's claim of this case is in conflict with the res judicata of the judgment of the previous

2. Determination as to whether the plaintiff's claim conflicts with res judicata of the previous suit

A. The facts of recognition (i) The Plaintiff’s total sum of KRW 372,98,00,000, advance payment deposit, and KRW 355,30,000, based on the subcontract agreement concluded between the Plaintiff and the Defendant on June 5, 2015 against the Defendant on April 19, 2016.