A wafer dividing apparatus for dividing a wafer whose strength is reduced along a plurality of dividing lines, along the dividing lines, which comprises a tape holding means for holding a protective tape affixed to one side of the wafer; and wafer dividing means, each comprising a plurality of tension application means comprising a first suction-holding member and a second suction-holding member for suction-holding the wafer held on the tape holding means through the protective tape on both sides of a dividing line, and moving means for moving the first suction-holding members and the second suction-holding members in such directions that they separate from each other.