A pattern forming system including a feeding reel for feeding a tape form substrate that is wound up, a winding reel for winding up the tape form substrate that is fed up, and a droplet discharge apparatus for discharging a droplet onto the tape form substrate, between the feeding reel and the winding reel, to form a pattern, wherein the droplet discharge apparatus includes a table that can move while sucking the tape form substrate, with a slack mechanism for the tape form substrate being placed on the both ends of the table in the longitudinal direction of the tape form substrate.