To make an outer case durable with pressure tight means even in its corner parts, and allowing the pressure tight means to be integral with the outer case in packing an object to be packed by holding the end parts with cushion material.

The end parts 1a of an article 1 are charged in the holding parts 21 of a cushion member 2 so as to secure the member 2 to the article 1. The cushion member 2 is made as a pulp molded product, and its sides opposite to the article 1 are formed into a converged shape, and spaces are defined between spacess in the proximity of the side surfaces 23 of the cushion member 2 and corner of the outer case 3 in the separation loading direction. Flaps formed integral with the outer case 3 at each corner of the outer case 3 are folded inward, thereby forming triangle pole-like pressure tight parts 4. As such, each pressure tight part 4 is put in a space between the cushion member 2 and the corner of the outer case 3.