To provide a compound container whose internally mounted thin container mouth peripheral edge is not separated from a mouth forming member fixed on the mouth part of an externally mounted metal can or a thick paper container even when the compound container filled with a content is dropped or toppled over by a load shift, etc. during transportation causing the metal can or the thick paper container to be deformed greatly.

In forming this complex container, a thin synthetic resin container 12 is internally mounted on a metal can or a thick paper container 11, and the mouth peripheral edge 18a of the container 12 is fixed on a mouth forming member 15 mounted on a mouth part 14 opening on the top panel 13 of the can or the paper container 11. At least near the mouth part 18 of the container main body 12a of thin container 12, an uneven part 22 for allowing extension is formed.