To provide a container used as a cooler/warmer which is excellent in versatility.

A container 20 is provided with a box-shaped main body 22 having an opening opened in one end and capable of including an article and a tray 56 and a lid 54 which are detachably engaged with each other as well as the main body, and is provided with a door assembly 52 capable of opening and closing the opening of the main body 22. The tray 56 can be rotated by 180° between a developed position at which the tray can be used as a top face of a fixed table and a position at which the tray is engaged with the lid 54, and the lid 54 can be opened independently of the tray 56 when the tray 56 is developed as the top face of the table, and is engaged with the container 20 in order to keep engagement between the tray 56 and the lid 54 while the lid 54 is opened from the container 20.