A blister package comprises a blister and a cover sheet, and the blister has a groove formed in an outer edge section of the blister. The outer edge section of the blister includes an outer region and an inner region, the groove is formed on the inward side of the outer region, and the inner region is formed on the inward side of the groove. The peel strength between the outer region and the cover sheet is greater than the tear strength of the cover sheet, and the peel strength between the inner region and cover sheet is smaller than the tear strength of the cover sheet.
