A. The plaintiff is a corporation that runs the business of managing, operating, maintaining, and repairing the Incheon International Airport Corporation, and the defendant is a company that runs a real estate rental business, etc.

B. On July 31, 2000, the Plaintiff and the Defendant entered into a concession agreement (hereinafter “instant agreement”) with the content that the Defendant would make its best efforts to perform the role as airport facilities in the construction and operation of business facilities (B4) in the international business area south of the Incheon International Airport Passenger Terminal (hereinafter “instant business”). The Defendant completed the instant business site in ELT officetels in accordance with the instant agreement.

Article 79 of the Convention provides that “The Defendant shall pay various ethyl rates after consultation with the Plaintiff.”

The Plaintiff, as a facility for the supply of electricity under the instant agreement, installed at its own expense a main transformation station, other transformation stations, power distribution transformation stations, cables, water transformation facilities, power distribution lines, etc. in the Incheon International Airport.

C. Since then, the Defendant submitted an application for electric use to the Plaintiff and obtained approval from the Plaintiff, and the said contract for electric use was governed by the Plaintiff’s terms and conditions of electric use, and Article 44 and attached Table / [4] of the terms and conditions of the said contract provides that “The Defendant shall pay KRW 17.75 per 1kWh (the first 24.6 won per 1kWhh, but the said amount was reduced to December 23, 2005) separately from the electric charges.”

On the other hand, the Plaintiff issued to the Defendant a written statement that “the standard for calculating electric charges (No. 4)” with the following contents separately from the terms and conditions.

On the other hand, on April 26, 2001, the Plaintiff concluded a provisional agreement with the Incheon Airport Energy Co., Ltd. on energy supply.