Provided is a potassium titanate powder that can avoid safety and health concerns and concurrently, during use in a friction material, can give excellent frictional properties. A potassium titanate powder is a powder formed of bar-like potassium titanate particles having an average length of 30 μm or more, an average breadth of 10 m or more, and an average aspect ratio of 1.5 or more, wherein the bar-like potassium titanate particles are represented by a composition formula K2TinO2n+1 (where n=5.5 to 6.5).