The objectives of this paper are to investigate the effects of auditory feedback and tactile feedback on usability of touch panel and to find out the improving mechanism of touch panel usability. Four kinds of stimulus conditions are prepared with the absence or presence of auditory feedback and vibration feedback. In experiments, subjects are given phone number task under the stimulus conditions. In order to evaluate the usability, task duration is measured by using timer counter function in the touch panels, and eye-fixation duration is measured with an eye tracking system. From the experimental results of 24 subjects, it was found that not only the task duration but also the fixation duration on the touch panel are influenced by the stimulus conditions. Accordingly, the reason why the task duration under the condition with auditory feedback or vibration feedback becomes shorter seems to depend on the fixation duration on the touch panel. Since it is well known that auditory reaction time and tactile reaction time are faster than visual reaction time, it was guessed that subjects could more quickly judge the completion of phone number input by using auditory and tactile senses.