A ball forming device 50 for forming a ball 43 at a tip of a wire 42 by producing discharge between a torch electrode 48 and the tip of the wire 42, the device includes: a current supply unit 54 configured to supply a ball-forming current between the torch electrode 48 and the tip of the wire 42; and a current control unit 57 configured to control the current supply unit 54, so that a signal of the ball-forming current for a predetermined period includes a first period in which the signal takes a predetermined current value and a second period including a triangle wave. With this, it is possible to provide a ball forming device, a wire-bonding apparatus, and a ball formation method that are capable of suppressing formation of deformed balls.