It is illegal to resell masks to earn the difference. Medical masks belong to medical devices, and it is illegal to operate without business qualifications. Generally, the amount is small enough to commit a crime, but the illegal income can be confiscated and a fine can be imposed.

According to the provisions of Article 225 of the Criminal Law of People's Republic of China (PRC), it refers to the crime of committing one of the following illegal business operations in violation of state regulations:

(a) without permission, dealing in franchise, monopoly goods or other commodities with restricted trading as stipulated by laws and administrative regulations;

(2) buying and selling import and export licenses, import and export certificates of origin and other business licenses or approval documents stipulated by laws and administrative regulations;

(three) without the approval of the relevant competent departments of the state, illegally engaged in securities, futures, insurance business or illegally engaged in fund settlement business;

(four) engaged in other illegal business activities, disrupting the market order, and the circumstances are serious.