A double-sterile package for critical-use medical apparatus includes an inner first container including an outer boundary wall impervious to microorganisms and being closed except for defining a hole. A patch of gas-permeable micro-porous sheet material is secured to the outer boundary wall spanning and closing the hole. The gas-permeable sheet material is sufficient to exclude environmental microorganisms from entering the inner first container. The first container is received into and nested within a conformal second container also having a boundary wall impervious to microorganisms and being closed except for defining a hole. This hole of the second container is also closed by a patch of the gas-permeable micro-porous sheet material, and the holes of the first and second containers are in gas-flow communication with one another. The medical apparatus within the nested containers is sterilized by evacuation of air and introduction of a sterilizing gas via the gas-permeable patches. Removal of the sterilizing gas provides a packaged sterile medical apparatus which may be transported, stored, and handled with no further need to additionally protect the sterility of the apparatus, or for further sterilization after the package is opened immediately prior to use of the apparatus.