To provide an extraction bag manufacturing device, extraction bag manufacturing method and extraction bag capable of increasing a volume of the extraction bag without increasing its vertical size and lateral size.

Since tea bags B1, B2 have gathers Ga, Gb, it is possible to attain a large volume without increasing a vertical size and a lateral size. Accordingly, a substantial amount of tea T can be stored without producing any inconvenience of state that the tea bags cannot be entered into a pot. In addition, since a wide surface area can be attained, an extraction of tea T can be sufficiently carried out.