To use a sharpener for sharpening a number of objects such as a knife, scissors, a chisel or the like, by providing a basic part of a cutter sharpener with such geometry that the cutter sharpener is alternated between one of the sharpening positions and the other sharpening position.

A cutter sharpener is inclined in a right direction at a first sharpening position, and is supported by an angle alternating means 14 and a first edge part 16. An user of the cutter sharpener slides a cutting edge of a knife downward from the uppermost part of a second leg 8 toward a second edge part 18. Whereby one blade face of the cutting edge of the knife is sharpened. Then the blade sharpener 2 is inclined in a left direction, placed on a second sharpening position, and supported by the angle alternating means 14 and the second edge part 18. Then the cutting edge of the knife is positioned near the uppermost part of a first leg 6, and the cutting edge of the knife is slid downward toward the first edge part 16. Whereby the blade face at an opposite side of the cutting edge of the knife is sharpened.