To provide an opening binder for balloons filled with food product in which a rubber balloon is filled with a food product such as frozen food or jelly-like food, for example, sweet jelly of beans and is automatically closed with a rubber band at its opening neck.

This rubber band-binder is equipped with a spiral rod 38 which is rotated horizontally between a rubber band hanging nail 26 and a rubber band-supporting pin 27 which reciprocates to the rubber band-binding position to form vertical and horizontal notch at its top end so that the notch may protrude from the rubber band-supporting pin 27, when it rotates, and with a hook rod 50 which is set inside the rubber band-hanging nail and has a hook 51 formed at its top end. A rubber band 6 set between the hanging nail 26 and the supporting pin 27 is fitted to its binding position of the balloon 7 and the balloon is forcedly filled with a food product. Then, the spiral rod 38 is rotated to remove the rubber band from the supporting pin 27 and allow to pass through the other end of the rubber band whereby the opening of the balloon is bound with the rubber band.