To provide a multi-purpose sleeping bag to be used as a backpack in common, easy to carry and formed in a compact manner.

This sleeping bag 10 to be used as a backpack in common is a sleeping bag including a substantially rectangular covering part 10 and a sheet part 14, wherein the sleeping bag is provided with a backpack construction part 25, which surrounds part of the sleeping bag to form a box-shaped backpack; the backpack construction part 25 is folded to connect the opposite parts each other in the periphery of the backpack construction part 25 and to be assembled into a box-shaped backpack, and is stored in the box-shaped backpack in a boundary to a non-backpack forming part in the periphery of the backpack construction part 25. The backpack construction part 25 is provided with a backsack belt part 48.