To provide a microwave oven-heated sterilization bag which prevents a burn from being caused when the bag is taken out from a microwave oven and when boiling water is removed after sterilization, and furthermore prevents the bag from getting broken when feeding equipment is put into or out of the bag and has high portability.

The sterilizing bag to be heated includes an opening to put an article to be sterilized into or out of the bag in the upper portion of the bag. The opening has a male die shaped Velcro fastener permitting the opening to be opened and closed attached to both sides of the inside of the bag.