This paper proposes a method of vibration control of a flexible arm by input shaping based on wave model. Through the wave model which is one of the distributed parameter system, we can consider the infinite numbers of resonance in the flexible arm. Using the inverse system of the flexible arm, we design the input shaper for vibration suppression. Based on the frequency analysis, we show the characteristics of the proposed input shaper based on wave model. Using a single link flexible manipulator, the proposed method is compared with the conventional methods considering the finite numbers of the resonance frequency. From the experimental results, the effectiveness of the proposed method has been confirmed in terms of Root Mean Squared Error (RMSE) and the settling time.