A vibration-proof device for an upper transparency adapter (UTA) of a scanner is provided. The vibration-proof device includes a supporter for coupling a slide rod mounted in a cover of the upper transparency adapter for an optic source carriage to be slidably coupled thereto, a positioning member for retaining in place the supporter in the cover and an elastic member interposed between the supporter and a base of the cover for providing the supporter with an upward elastic force so as to resiliently abut the optic source carriage against a glass panel attached to the cover.