1. The plaintiff's claim is dismissed.

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

Basic Facts

The plaintiff is a company that operates the sales business of fire-fighting machinery, equipment, etc. and the construction business of specialized fire-fighting equipment, etc., and the defendant is a mutual aid association established under the Framework Act on the Construction Industry to provide necessary guarantee, financing and mutual aid to the construction business operators who operate the

On August 29, 2017 between the Plaintiff and C, the Plaintiff entered into a contract with Sejong Special Self-Governing City E (hereinafter referred to as “instant construction”) with the contractor D (hereinafter referred to as “D”) to supply sewage by fixing the contract amount of KRW 2,901,80,000 (including value-added tax; hereinafter the same shall apply) and the construction period from August 29, 2017 to October 31, 2018; thereafter, the Plaintiff entered into a contract to change the contract amount of KRW 3,119,60,000 and the construction period from August 29, 2017 to December 20, 2018 (hereinafter referred to as “instant contract”).

On August 29, 2017, the Plaintiff entered into a contract with C (hereinafter “C”) for the supply of construction works with the content that “the instant construction works-supply and construction works” is to provide contract amounting to KRW 2,516,80,000 on August 29, 2017, the date of commencement, and June 30, 2018 on June 30, 2018, the date of completion, and the contract deposit was to provide contract performance guarantee securities (the amount of guarantee is 10% of the contract amount, the guarantee period is 60 days of the contract period). Since then, the Plaintiff entered into a modified contract with the content that the contract amount on September 20, 2018 is changed to December 20, 2018 (hereinafter “instant contract”).

The guarantee period of F 251,680,00 on September 7, 2017, F251, F251,680,000 from August 29, 2017 to October 11, 2018, is the changed guarantee due to the extension of the guarantee period of No. 1, 251,680,00 on September 7, 2017.

From August 29, 2017 to February 19, 2019 to October 11, 2018, G 47,801,600 to September 20, 2018 to February 19, 2019, C’s failure to perform the instant contract between the Defendant and C.