To solve such problems in drying underlay pads, mattresses and pillows because of flow out of blown air for summer or light coverlets covering a bag for Futon mat driers, flowing out the air through a clearance between the coverlet and the underlay pad with the inflating of the bag by the blown air and flowing out the blown air through a connection part as it is of a breathing one-piece type, and also a problem such as lack of function of preventing the slipping of the coverlets off beds during the sleeping even when bed covers folded near feet, are moved near the breasts of users.

In the bag for Futon mat driers herein provided, the underlay pads, the mattresses and pillows are dried without making the blown air escape. Moreover, an upper fabric of the bag for the Futon mat drier can be utilized as a bed cover while the coverlet can be kept from slipping off the bed during the sleeping.