1. Of the judgment of the court of first instance, the money that orders the following payment concerning the principal lawsuit is corresponding to the plaintiff (Counterclaim defendant).

A principal lawsuit and a counterclaim shall be deemed simultaneously.

1. Basic facts

A. The Plaintiff is a business entity that assembles and supplies electronic parts in the name of D, and the Defendant is a business entity that runs metal heat treatment business in the name of E.

B. On April 2010, the Plaintiff entered into a contract with the Defendant for the manufacture and supply of hydrogen inputs, Otombls, etc. (hereinafter “instant equipment”) that constitute high-frequency heat processing machinery for metal heat processing at KRW 51,700,000, including value added tax (hereinafter “instant contract”). The instant contract concluded that the instant equipment was intended to be remodeled into two high-frequency heat processing machinery with the Defendant, which was already used by the Defendant, by adding the instant equipment to the existing high-frequency heat processing machinery.

C. On May 11, 2010, the Plaintiff received KRW 20,000,000 from the Defendant as part of the above payment, and KRW 10,00,000 on June 11, 201, and delivered the instant device to the Defendant around July 30, 2010.

[Ground of recognition] Unsatisfy, entry of Gap evidence 1 to 4, purport of whole pleadings

2. The parties' assertion

A. The plaintiff completed the delivery of the device of this case under the contract of this case. Thus, the defendant asserts that the plaintiff should pay to the plaintiff 21,700,000 won (=51,700,000 won - (20,000,000 won) which is the unpaid amount out of the price of the goods stipulated in the contract of this case and damages for delay.

B. As to this, the Defendant did not go through a trial run after the Plaintiff installed the device, and the machinery of this case does not work properly since it did not repair the defects occurring in the device thereafter. Thus, the Plaintiff cannot be deemed to have completed the performance of the contract of this case, and the Defendant cannot respond to the Plaintiff’s claim. As a counterclaim, the Defendant provided the Plaintiff with the goods amounting to KRW 30,000,000 and the goods amounting to KRW 30,000,000, which were incurred by the Plaintiff due to the Plaintiff’s nonperformance of obligation as above