A glass cutter is provided which can form, using a wheel, a uniform crack in glass even when a projection or an earlier-formed scribe line is present on the glass. When the wheel is moved on the glass, a fracture layer is formed causing a rib mark to be formed below the fracture layer and a crack to be formed below the rib mark. To cut the glass, the crack is required to be formed uniformly. Applying a force to resist the rotating force of the wheel makes it possible to form a uniform crack even when a projection is present on the glass. This improves glass cutting yield.