As higher operating speeds are enabled for presses and machine tools, higher quality is demanded for paper and paperboard used. Conventionally, as provided in the J.TAPPI and TAPPI UM standards, the Z-direction strength has been tested with a tensile or bursting tester that measures static strength. With that method, however, it is difficult to grasp behaviors of paper under actual operating conditions. This tester provides reliable information as a tester specialized in measurement of the following: bonding strength of coated paper, Kraft paper and laminated paper, delamination resistance of paperboard, and film adhesion strength. This tester works as follows. A specimen with one-inch-wide tape attached on both sides is placed on the specimen stage. An aluminum angle is fixed on the specimen. Then that specimen stage is fixed in a holder, and a hammer is struck from a horizontal position to impact on the aluminum angle. Part of the specimen should come off together with the aluminum angle. When the angle comes off, the energy loss of the hammer can be read on a scale.