The invention relates to a device (1) for sharpening the blade of a manual cutting tool, in particular a knife. The inventive device comprises a support (2) provided with a cutout (4). Identical sharpening levers are arranged on each side of the cutout in front and in staggering manner with respect to each other and provided with a curved arm (13) having a rectilinear end edge (14) and another arm (16) forming means for returning in a position by gravity. Each lever (11) is pivotally mounted in the jointing area (15) of the arms (13, 16) around an geometrical axis which is generally perpendicular to a longitudinal direction (A-A') of the cutout and a slot (5). Said device is particularly adapter to the agriculture and food industry.