PURPOSE: To easily unpack a corrugated fiberboard box by forming a finger hook hole on an upper part of right and left side walls of an individual case made of corrugated fiberboard and forming a push-in tab surrounded by perforations for cutting a lid on opposite portions of the lid overlapping the finger hook hole.

CONSTITUTION: Three individual cases A made of corrugated fiberboard are laterally connected for constituting a coupled case body with a top wall and right and left side walls covered by lids C having a U-shaped cross-section and made of corrugated fiberboard, wherein a finger hook hole 10 to be used when peeling off top walls 1, 1 made of folded pieces is formed on an upper part of the right and left side walls 3 of the individual. case A which can receive three to six pieces of products such as shampoo or detergent. Cutting lines and folding perforations are alternately formed at fold line positions at borders between front and rear walls 2 and the top wall 1. A push-in tab 23 surrounded by perforations 22 for cutting off a lid is provided so that it can be cut off from the side wall of the lid C on an opposite portion of the lid C overlapping the finger hook hole 10.