To provide a container lid which can prevent a content from boiling out when being fitted on a container which houses a retort food or the like cooked in a microwave oven or the like, and through which the retort food or the like can be seen.

For this container lid, a non-contact plate part 8 is formed in order to form a space 7 to a content, under a state wherein the lid is fitted on a container main body 2. The volume of the space 7 is set to be 4% of the content housing space of the container main body 2, and also, the area of the non-contact plate part 8 is set to be 25% of the area of the opening 4 of the container main body 2.