1. Revocation of the first instance judgment.

2. The plaintiff's claim is dismissed.

3. All costs of the lawsuit shall be borne by the Plaintiff.

1. Basic facts

A. The Plaintiff is a person who operates construction machinery leasing business under the trade name of “B” and the Defendant is a mutual aid association with the aim of promoting the autonomous economic activities and the elevation of economic status of its members by providing necessary guarantees, financing and mutual aid services to its members.

B. On August 25, 2015, the Plaintiff prepared a construction machinery lease agreement (hereinafter referred to as “instant lease agreement”) that leases construction machinery leased as one,6.5 million won (including additional tax), period of use from August 25, 2015 to September 10, 2015 (including additional tax), and one,6.5 million won (including additional tax) per month from August 25, 2015 to September 25, 2015 (hereinafter referred to as “instant construction machinery”).

C. On September 1, 2015, Seobu Construction concluded a guarantee agreement with the Defendant (hereinafter “instant guarantee agreement”) on September 1, 2015 in order to secure the payment of the Plaintiff’s loan for construction machinery under the instant lease agreement, and issued a guarantee certificate stating the following (hereinafter “instant guarantee certificate”).

- Guarantee amount of KRW 16.5 million - Guarantee period: A construction machinery rental business operator under the Construction Machinery Management Act - A construction machinery rental business operator under the Construction Machinery Management Act - A construction site: A construction site: A construction site: A construction site: A construction site: A civil engineering works/electronics, and designated construction works at the D community service center.

D. Of the terms and conditions of construction machinery rental guarantee applicable to the instant guarantee agreement, the relevant contents of the instant contract are as follows.

Article 1 (Guarantee Responsibility) Specialized Construction Mutual Aid Association (hereinafter referred to as the "Association") is related to the front entry contract due to reasons attributable to the contractor (hereinafter referred to as the "debtor").