1. The defendant's appeal is dismissed.

2. The costs of appeal shall be borne by the Defendant.

3. Paragraph (1) of this Article, among the judgment of the court of first instance;

1. We examine the legitimacy of the subsequent appeal of this case ex officio, based on the determination on the legitimacy of the subsequent appeal of this case.

Article 173(1) of the Civil Procedure Act provides that “Any reason for which a party cannot be held liable” refers to a reason why the party could not observe the relevant period even though the party had exercised a general duty to act in the course of litigation. In a case where the document of lawsuit cannot be served in a usual way while the lawsuit was in the course of litigation and served by public notice, the document of lawsuit cannot be served in a way of service by public notice. As such, the party is obligated to investigate the progress of the lawsuit even if the party fails to investigate the progress of the lawsuit and fails to abide by the peremptory period, it cannot be said that the party is attributable to a reason for which the party cannot

(1) According to the records, the court of first instance issued an order to correct the Plaintiff’s address when the Plaintiff served the copy of the instant complaint to “Seoul Jongno-gu 3rd floor,” which is the Defendant’s domicile indicated in the complaint, but it was impossible to serve the original copy due to the addressee’s unknown address, and the Plaintiff corrected the Defendant’s address to “Seoul Jongno-gu D and 3rd floor” (hereinafter “instant address”), and the court of first instance received the duplicate of the complaint to the address of this case on December 29, 2015. (2) The court of first instance sent the notice to the address of this case but sent the notice to the address of this case without a written notice, and (3) the court of first instance ordered the Defendants to serve the original copy to serve the Defendant by public notice on April 1, 2016 by public notice. (4) The court of first instance ordered the Defendants to serve the original copy to the Defendant by public notice on April 1, 2016.