Abstract: The device of the invention can be used for evaluating the cutting ability of knives and other like cutting tools. The device includes a rigid body (2) with a slide (10) receiving a foam rod (12), and a bearing surface (8) substantially perpendicular to the slide (10) for positioning and guiding the cutting tool (16) to be tested. The foam rod (12) includes two visually discernible portions (13, 14) placed one above the other, and in particular having different colours, and is placed in the slide (10) so as to project from the front of the bearing surface (8). The test comprises cutting the protruding end of the rod (12) by reciprocating (F) the tool (16), and assessing whether the blade (15) has cut only the upper portion (13) or both portions (13, 14) of the rod. The device can be used for testing knives, surgical instruments, farming and gardening tools, industrial cutting tools, etc.