A fastening apparatus and a holding rack which includes a holding dock, a holding device and the fastening apparatus. The holding device has a holding bracket and a fastened member. The fastening apparatus includes a collet and a sleeve. The collet has a bottom and a plurality of jutting plates. The collet is mounted onto the holding dock to hold the fastened member. The jutting plates are located longitudinally on the bottom in a protrusive manner. Each of the jutting plates has an outer surface on which a portion is extended outwards greater than other portion. The collet is encased in the sleeve. The sleeve has a tubular wall which has a plurality of segments corresponding to the jutting plates. Each segment has an inner surface on which a portion is extended inwards greater than other portion. When the greater extended inward portion of the tubular wall is in contact with the greater extended outwards portion of the jutting plate, the jutting plate is tilted inwards to press the fastened member.