Hi! I work 8 hours a day from 09:00 to 18:00, Monday to Friday with the one hour lunchtime excluded. I do not work on weekends. Currently, I receive a basic salary of 1.7 million won per month, a meal allowance of 300,000 won. My boss has told me that he cannot raise my salary due to managerial constraints. I wonder whether my current salary violates the Minimum Wage Act in 2020.?

The Minimum Wage Act applies to all workers who work in Korea regardless of nationality. (Excluding businesses that employ only relatives residing together, housekeepers, sailors subject to the Seamen Act and ship owners who use seamen, and workers who are significantly less able to work due to mental or physical disability and as accredited by the Minister of Employment and Labor)
The minimum hourly wage for 2020 is 8,590 won. Based on administrative analysis of the Ministry of Employment and Labor, your minimum wage would be for eight hours a day, 40 hours a week, plus eight paid holiday hours per week under Article 55 of the Labor Standards Act, for a total of 48 hours paid per week. Since a month consists of an average of 4.345 weeks (365 days/12 months/7 days), the average monthly paid time is approximately 209 hours (48 hours × 4.345 weeks). Your minimum monthly wage should be 1,795,310 won (209 hours × 8,590 won) or more, but your basic monthly salary is 1.7 million won, which is below the minimum wage.
However, the Minimum Wage Act was amended in January 2019. Under the amended Minimum Wage Act, regular bonuses and cash welfare benefits, such as meal, lodging, and transportation allowances paid on a monthly basis will be counted when calculating minimum wage; therefore when calculating the minimum wage for 2019, at least 25% of regular bonus and at least 7% of welfare benefits will be included in calculating minimum wage. Moreover, the percentage will gradually increase on an annual basis, so that from 2024, all regular bonuses and welfare benefits will be included.

In your case, because a certain amount of meal allowance is included in calculating the minimum wage, your actual wage is about 1.81 million won per month, which is higher than minimum wage (1,795,310 won), and therefore it does not constitute a violation of the Minimum Wage Act coming into effect in 2020.