Abstract: A knife sharpener is made up of a housing containing a sanding belt and a driving system that engages the belt to cause it to move in a sharpening area where a knife can come into contact with the sanding belt. The knife sharpener also includes a first angle guide having a surface against which a first side of a knife can be positioned so the edge of the knife can be positioned in the sharpening area, a second angle guide having a surface against which a second side of the knife can be positioned so the edge of the knife can be positioning in the sharpening area, and an angle adjustment mechanism that can adjust the angle of the first angle guide and the second angle guide to change the angle of the surfaces relative to the sanding belt.