Abstract: The invention provides a fastener tape supply unit applied to a continuous manufacturing apparatus for a fastener stringer, wherein a dancer roller moving up and down corresponding to changes in tape tension is loaded on a fastener tape carried between a feed roller portion for feeding the fastener tape continuously and positively and an engaging element implantation portion, upper and lower limit positions of the dancer roller are detected by detecting means, and when the dancer roller goes out of a range defined by the upper limit position and the lower limit position, a corresponding detection signal is sent to a control portion, the control portion outputs an instruction signal for always holding the dancer roller between the upper and lower limit positions to a drive portion of a drive roller, thereby controlling a tape feeding amount of the feed roller portion to be always constant.