An end user container for food in refrigerated storage and subsequent microwave cooking is made of a thermo-plastic material transparent to radiant energy. The lid and tray are thermo-formed pieces and incorporate latches as integral features in the respective parts. They are arranged with a post-in-socket capability for latching the lid to the tray in a position which will permit venting of the interior of the container assembly to the exterior. The rims of the tray and lid are formed to enable pressing them together providing a surface sealing between the tray and lid along engaging wall portions of the lid and tray continuously around the container. Also, the lid has a bottom cooperating with the wall to provide a well, and the wall of the tray is outwardly turned, providing a step or ledge near the top of the tray and extending out to the upper wall portion, forming a part of the rim and which engages the well wall when the container is closed to the seal condition. When it is in the venting condition, the latches enable a perimeter space between those walls and around the entire container.