The judgment of the court below is reversed, and the case is remanded to Daejeon High Court.

The grounds of appeal are examined.

1. As to the validity of the instant agreement and the violation of the principle of good faith, Article 4(1) of the Act on the Protection, etc. of Fixed-Term and Part-Time Workers (hereinafter “ Fixed-Term Act”) provides that “An employer may appoint a fixed-term worker within the extent not exceeding two years (in the case of the repeated renewal of a fixed-term employment contract, the total period of continuous employment shall not exceed two years).” Meanwhile, the proviso to paragraph (1) provides that “If a fixed-term worker is employed for more than two years despite the absence or extinguishment of the grounds under the proviso to paragraph (1), the fixed-term worker shall be deemed an employee who has concluded an employment contract without a fixed-term worker.”

The legislative purport of the above provisions is to guarantee workers’ status by preventing abuse of fixed-term employment contracts (see Supreme Court Decision 2014Du45765, Nov. 10, 2016). As such, Article 4(2) of the Fixed-term Act ought to be deemed a mandatory provision.

Therefore, even if the parties to a labor contract agree to exclude the Article 4 (2) of the Fixed-term Act, the validity is not recognized.

On the other hand, the principle of trust and good faith (hereinafter “the principle of trust and good faith”) refers to an abstract norm that a party to a legal relationship should not exercise rights or perform obligations in such a way as to be contrary to equity or trust in consideration of the other party’s interests.

In order to deny the exercise of rights on the ground that the exercise of rights is contrary to the good faith principle, it should be given to the other party, or it should be objectively viewed that the other party has good faith. In light of the concept of justice, exercising rights against the other party’s good faith.