The metal melt filtration is a treatment to improve the product quality of casted products. The outstanding characteristic of metal melts is the non-wetting of the fluid with the particulate impurities and the used filter. Adhesion forces between a particle and substrate are measured by atomic force microscope for different wetting conditions. It is shown that the wetting angle between the particles and the fluid has an influence on the adhesion force and a significant effect on the filtration efficiency.