The judgment below is reversed and the case is remanded to Seoul High Court.

The grounds of appeal are examined.

1. The act of subsidizing wages to a worker who is not merely a full-time worker but does not have been designated as a time-off worker itself becomes an unfair labor practice, but the act of paying wages to a time-off worker is, in principle, not an unfair labor practice, unless there are special circumstances.

However, in light of the purpose of the main year of the working hours exemption system that allows the time-off worker to engage in labor union activities without economic losses after being exempted from working hours under the duty to provide labor, the wages paid to the time-off worker shall be equivalent to the working hours for which the duty to provide labor is exempted.

Therefore, even if a collective agreement between labor and management is reached, an employer’s act of paying excessive wages to a person who is exempted from working hours without justifiable grounds may constitute an act of providing wages for full-time union workers or providing assistance in operating expenses of a trade union as exceeding the scope permitted under the proviso of Article 81 subparag. 4 of the Trade Union and Labor Relations Adjustment Act (hereinafter “Trade Union Act”).

In this context, whether payment of wages to a time-off worker is excessive and thus constitutes unfair labor practices should be determined by examining circumstances such as excessive payment of wages to the extent that it exceeds the reasonable scope acceptable under generally accepted social norms, such as the level of wages or payment criteria received by a time-off worker, if he/she worked for an ordinary worker not designated as a time-off worker but as a time-off worker.

(see Supreme Court Decision 2014Du11137, Apr. 28, 2016). 2. Reviewing the reasoning of the lower judgment, the lower court is based on adopted evidence.