The appeal is dismissed.

The costs of appeal are assessed against the Defendant-Counterclaim Intervenor.

The grounds of appeal are examined (to the extent of supplement in case of supplemental appellate briefs not timely filed).

1. The reasoning of the lower judgment on basic facts reveals the following facts.

The Defendant (Counterclaim Plaintiff; hereinafter “Defendant”)’s Intervenor (hereinafter “Supplementary Intervenor”) provided the Plaintiff (Counterclaim Defendant; hereinafter “Plaintiff”) with each equipment system (Glas Sing Symm; hereinafter “instant equipment”) through the Defendant, and the Defendant issued the Plaintiff a letter of intent to purchase on April 2013.

Since then, the Plaintiff, the Defendant, and the Intervenor met several times regarding the design, manufacture, and installation of the instant equipment. On May 29, 2013, the Plaintiff submitted a written estimate to the Defendant, specifying the items, quantity, unit price, etc. constituting the instant equipment.

On May 30, 2013, the Defendant paid KRW 1,056,00,000 to the Plaintiff as advance payment for the manufacture and installation of the instant equipment.

B. As to the manufacturing and installation of the instant equipment, the auxiliary intervenor contracted to the Defendant on June 20, 2013 the price of KRW 3.5 billion (excluding value-added tax), and on June 24, 2013, the Defendant subcontracted to the Plaintiff on June 24, 2013 the price of KRW 3.2 billion (excluding value-added tax).

(hereinafter “instant contract”). The main contents of the instant contract are as follows.

(1) The product shall be manufactured in accordance with a quotation, etc.

The intermediate payment shall be paid within 14 days after the completion of the storage of the product with 50% of the contract amount, and the balance shall be paid at the end of the following month after the completion approval for the final inspection of the contract amount.

The payment date shall be July 30, 2013.

(2) The Plaintiff must immediately commence the installation work after delivering the product to a place designated by the Defendant, and conduct a trial run in the presence of the Defendant, and request the Defendant to conduct the final inspection.

The defendant shall conduct a final inspection on the product in accordance with the quotation and other agreed evaluation criteria, and shall make a written statement as to whether the product passes.