Disclosed is a CMP slurry for silicon film polishing, comprising abrasive grains, an oxidizing agent, a cationic surfactant, and water. This CMP slurry is suitable for the CMP step of a silicon film of semiconductor devices, since it enables to obtain excellent planarity and excellent performance of controlling the remaining film thickness, while improving the yield and reliability of the semiconductor devices. This CMP slurry also enables to reduce the production cost.