When an inner cover portion is accommodated in a blister pack, a retention space area a for accommodating a capsule endoscope is formed between the bottom face of the inner cover portion and the inside bottom face of the blister pack. The capsule endoscope, retained by a retaining portion formed in the blister pack and by a hole portion formed in the inner cover portion, is set into a storage case. The entire capsule endoscope accommodated in the storage case is uniformly and satisfactorily sterilized by blocking the opening of the blister pack with a sterilizing sheet.