Packaging box and packaging method

A packaging method comprising:

• using a packaging box comprising a shelf portion which partitions an interior of the packaging box into an upper space and a lower space, an inner flap which is located above the shelf portion as an inner lid and which is bendable to a closed position where the inner flap faces the shelf portion while extending parallel thereto, and a hold-down piece which is disposed at a position facing the inner flap at the closed position in the shelf portion and which the hold-down piece formed by cutting and raising the shelf portion to be capable of standing in a tilted state where a distal end side thereof extends toward a first side portion,
• causing the hold-down piece to stand in the tilted state where a distal end portion of the hold-down piece is located above a lower surface of the inner flap at the closed position;
• placing an object to be packaged on the shelf portion such that the object to be packaged comes into contact or is capable of coming into contact with a tilted portion on a base side of the hold-down piece, and bringing the inner flap to the closed position and causing the inner flap to bias the hold-down piece in the tilted state downward to cause the packaging box to hold the object to be packaged between the tilted portion and each of the shelf portion and the first side portion by changing a tilt angle of the hold-down piece with respect to the shelf portion to form an oblique angle.