Article 23 (Restriction on Dismissal, etc.), Article 28 (Request for Remedy from Unfair Dismissal, etc.),
Article 107 (Penalty Provisions), Labor Standards Act, as last amended by Act No. 12325, Jan. 21, 2014

No employer can terminate the contract unilaterally without a justifiable reason.
When an employee unfairly dismissed, he/she can file a case for remedy to the Labor Relations Commission. If the Commission judges that it is an unfair dismissal, then the company should reinstate the employee and pay retroactively during the unfairly dismissed period.

Especially, an employer cannot dismiss a worker during a period of suspension of work for medical treatment of an occupational injury or disease and within 30 days immediately thereafter, and any woman before and after childbirth. If an employer violates the Article, s/he shall be punished by imprisonment for not more than five years or by a fine of not exceeding 30 million won.

*Labor Standards Act

Article 23 (Restriction on Dismissal, etc.)(1) An employer shall not, without justifiable cause, dismiss, lay off, suspend, or transfer a worker, reduce his/her wages, or take other punitive measures (hereinafter referred to as "unfair dismissal, etc.") against him/her.

(2) An employer shall not dismiss a worker during a period of suspension of work for medical treatment of an occupational injury or disease and within 30 days immediately thereafter, and any woman before and after childbirth shall not be dismissed during a period of suspension of work as prescribed by this Act and for 30 days immediately thereafter: Provided, That this shall not apply where the employer has paid a lump sum compensation as provided for under Article 84 or where the employer may not continue to conduct his/her business.

Article 28 (Request for Remedy from Unfair Dismissal, etc.)(1) When a worker is subjected by the employer to any unfair dismissal, etc., he/she may request a remedy therefor from a labor relations commission.

(2) A request for remedy under paragraph (1) shall be made within three months from the date of the unfair dismissal, etc.

Article 107 (Penalty Provisions)

A person who has violated Article 7, 8, 9, 23 (2) or 40 shall be punished by imprisonment for not more than five years or by a fine of not exceeding 30 million won.