In a closed loop control method of a linear vibration actuator which vibrates linearly and energized by a switching element driven in a PWM control method, a crest or peak point (Bc, Bp) of the back electromotive force occurring in the linear vibration actuator is detected (S14). The detected crest or peak point (Bc, Bp) is compared with a reference value (Bcr, Bpr) (S15), and adjusting the PWM duty (α) applied to the switching element and controlling the operating frequency of the linear vibration actuator to resonant frequency (S16 to S19), thereby keeping the crest or peak point (Bc, Bp) of the back electromotive force always constant.