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

The grounds of appeal are examined.

1. As to whether the intervenor joining the defendant constitutes a worker

A. Workers under the Industrial Accident Compensation Insurance Act mean workers under the Labor Standards Act.

(Article 5 subparag. 2 of the Labor Standards Act). Determination of whether a person is a worker under the Labor Standards Act should be made depending on whether the substance of the labor provision relationship is a subordinate relationship to an employer, rather than whether a contract is an employment contract, a contract, or a delegation contract.

In this context, whether an employer has a subordinate relationship should be determined by comprehensively taking into account the following economic and social conditions: (a) whether an employer determines the content of work and is subject to the rules of employment or service; (b) whether an employer is subject to considerable direction and supervision during the performance of work; (c) whether an employer is bound by the employer; (d) whether an employee is capable of operating his/her business on his/her own account, such as possessing equipment, raw materials or tools of work; (e) whether an employer has a risk, such as creation of profit and loss by providing labor; (e) whether the nature of remuneration is the subject of work; (e) whether the basic pay or fixed pay was determined; (e) whether the continuity and degree of the relationship of provision of labor; and (e) whether an employer has exclusive responsibility for the employer; and (e) whether an employer

However, the circumstances such as whether the basic wage or fixed wage has been determined, whether the labor income tax has been withheld, and whether the social security system has been recognized as an employee are highly likely to be arbitrarily determined by the employer by taking advantage of the economic superior position.