To easily distinguish a container with a poison injected as its appearance has changed to prevent damage before happens by a method wherein the container cannot be patched if it is bored or abnormality which cannot be easily repaired remains on a surface of the container even if it has been patched.

This container preventing a poison from being mixed comprises a can 1 coated 4 with a release agent such as silicone or Teflon on a surface. Thus even if a hole 2 is made and it is to be hidden by applying a patch 3, a can surface can be released from the patch. That is, since a pressure-sensitive adhesive cannot stick to a coating such as silicone or Teflon, the patch cannot be applied but easily releases 5 to have the hole 2 exposed. Further, since content liquid in the can may leak from the hole to contaminate the can or the like, mixture of a poison cannot be concealed to prevent damage. In addition, by coating styrene on the can surface, the hole 2 if bored causes the styrene coating to crack, and since patching the hole 2 cannot conceal the crack, a can with a poison mixed can be found.