To mechanize a process for gathering a curtain when a curtain with gathers is produced.

The apparatus for gathering a curtain has a roller head 30, an upstream-side clamp head 40 and a horizontally moving structure 20. The roller head 30 has upper and lower pair of delivery rollers 31 and 31 for nipping a gather tape 62 for the curtain and delivering the tape to the downstream side. The upstream-side clamp head 40 clamps each one end of a plurality of drawstrings penetrating the gather tape 62 in parallel. The horizontally moving structure moves while carrying the roller head 30. A biting track for restricting only the tape cloth 62a of the gather tape 62 and a through track allowing the drawstrings 62b to move are installed in the outer periphery of each delivery roller 31. The gathers are imparted to the gather tape 62 by the difference of speeds between the speed V1 of sending the tape cloth 62a of the gather tape 62 by the biting track of the delivery rollers 31, and the speed V2 of sending the drawstring 62b to the delivery rollers 31 by moving the head roller 30 through the horizontal moving structure 20.