To effectively improve a sense of balance and a posture.

On a foot mounting table 1 on which a user mounts both feet and stands, vibrators which individually give vibration stimulation within a range from 30 Hz to 200 Hz to a plurality of parts of the user's sole are disposed. The posture improvement device includes a center of gravity detection means for detecting a center of gravity of the user and a frequency analysis part for analyzing frequencies of a right and left component and a back and forth component of shaking at the center of gravity position obtained by the center of gravity detection means. A vibration control unit for controlling individual vibration of the vibrators vibrates the vibrators at a symmetrical position with respect to the center of gravity position calculated by a center of gravity position calculation means and switches vibrators vibrating with frequencies belonging to a frequency band of large power spectrum obtained by the frequency analysis part. A vibration stimulation part changes as the posture of the user changes and switch of parts the vibration stimulation is given is performed with frequencies in accordance with a frequency of center of gravity shaking.