To obtain a battery packaging means which can be entirely reused without need of classification.

A corrugated fiberboard packing case 1 receives a parallelopiped battery 2 with a reinforcing material 4 placed on an upper surface of the battery 2. The reinforcing material 4 is formed by folding a corrugated fiberboard into a rectangular tube. A developed structure of the material 4 has four planes including first to fourth parallel planes which are contiguous in a line, wherein a flap-like insert is made to protrude at an end of the first plane, and a cut into which the insert is fitted is provided on the fourth plane.