1. Article 485 of the Civil Act imposes an obligation to preserve a security on a creditor in order to protect a guarantor or other legal subrogation and secure a right to indemnity against a principal debtor. The creditor is either the original creditor or the person who becomes the creditor due to future subrogation, or there is no reason to distinguish them. If one of the joint and several sureties has jointly discharged from payment or other joint and several sureties at his own expense, apart from the fact that he can exercise a right to indemnity against the portion to be borne by another joint and several sureties under Articles 448(2) and 425 of the Civil Act, the obligee can naturally exercise a right to indemnity against the principal obligor within the scope of the right to indemnity under Article 481 of the Civil Act. The other joint and several sureties who redeems the said joint and several sureties's share to the said joint and several sureties shall be deemed to be the obligee within the scope of the right to indemnity again against the principal obligor, and the said joint and several sureties who has been released from the obligation to indemnity by subrogation of the principal obligor or the other joint and several sureties's loss of the obligation.

2. According to the reasoning of the judgment below, on March 8, 1990, the non-party jointly and severally guaranteed the non-party on the same day and the non-party on the facility lease contract of this case (hereinafter "the contract of this case") entered into with the Korean Enterprise Lease Co., Ltd. (hereinafter "the non-party") with the non-party on the same day, and the non-party did not perform the obligation under the contract of this case thereafter, the plaintiff did not pay the non-party 18,673,549 won in total of the principal and interest on the debt of this case under the contract of this case until April 1993, the non-party 18,673,549 won in the non-party company. As to the period of this case, the non-party 125,00,000 won in transfer from the non-party company and registered the change of the mortgage holder in the name of the plaintiff on June 7, 199.

However, the court below rejected the defendant's assertion that the defendant, a statutory subrogation, who caused the plaintiff's negligence to extinguish the value of the mid-term season of this case, is exempted to the extent that it cannot be repaid due to the loss of the above collateral under Article 485 of the Civil Code, on the ground that, inasmuch as the plaintiff, one of the joint and several sureties, is not able to exercise the right to indemnity against the plaintiff due to the repayment to the non-party company, and the defendant, a joint and several sureties, who is another joint and several sureties, cannot exercise the right to indemnity against the non-party company, and thus, the "amount that is not able to be repaid" from the plaintiff cannot be claimed as the discharge from liability pursuant to Article 485

However, in light of the above legal principles, in a case where it is acknowledged that the secured value of the above mortgage, which can be subrogated when the defendant performed the obligation of compensation as asserted by the defendant, has ceased to exist due to the plaintiff's negligence, the defendant can be exempted from the obligation of compensation against the plaintiff as long as it is impossible to recover from the non-party

Nevertheless, the lower court did not determine whether the Defendant was unable to receive reimbursement from the Nonparty due to the extinguishment of the collateral value of the said mortgage, but rejected the Defendant’s assertion of exemption due to the loss of collateral on the ground that the Defendant was unable to exercise the right to demand reimbursement from the Plaintiff and the Defendant did not have any amount that could not receive reimbursement from the Plaintiff. Therefore, the lower court erred by misapprehending the legal doctrine under Article 485 of the

3. Therefore, without further proceeding to decide on the remaining grounds of appeal, the judgment of the court below is reversed, and the case is remanded to the court below for a new trial and determination. It is so decided as per Disposition by the assent of all participating Justices on the bench.

Justices Yang Chang-soo (Presiding Justice)