A food container has a temporary rim formed in one-piece structure on the edge thereof. It has as first sealing rim and a second sealing rim as the surface for a sealing film to be heat-sealed thereon. When the outer rim is torn off, an irreversible tear-off structure on the sealed cover would leave the trace, allowing the consumers and the sellers to decide whether to purchase or dispose of the goods simply by visual judgments; in other words, it has a tamper-proof function. In addition, when the outer rim is removed from the container, the sealing film would detach from the first sealing rim but still stick on the second sealing rim, providing a reusable sealed cover for the container that ensures more safety of food hygiene.