To provide a polishing apparatus that efficiently polishes a substrate.

The polishing apparatus includes: a polishing pad; a turn table; a supply nozzle; a vibration supply unit; and a wall surface. The polishing pad is brought into press-contact with a surface to be polished of the substrate to chemically and mechanically polish the surface to be polished. The polishing pad is placed on the turn table. The supply nozzle drips a polishing agent on the polishing pad. The vibration supply unit adds vibration energy to the polishing pad. The wall surface is erected in an outer periphery of the polishing pad to surround a side surface of the polishing pad with the wall surface that is higher than the level of an upper surface of the polishing pad.