A packaging container includes: first fold sections for folding therealong, each of the first fold sections being provided longitudinally in a substantially central part of the first opposing side plate; second fold sections for folding therealong, each of the second fold sections being provided on the first bottom plate forming flap as an extension of the first fold section; and third fold sections for folding therealong, each of the third fold sections being provided on the first top cover forming flap as an extension of the first fold section. The second opposing side plate is equal to or smaller than the first opposing side plate in width. This makes it possible to fold up the packaging container easily and compactly.