PURPOSE: To provide a knapsack which can be carried in various forms and improves amenity by mounting casters to the lower part of a band carried on a user's back located on the back of a knapsack body and mounting a handle, held by a hand during running movement by using the casters, to the upper part thereof.

CONSTITUTION: A band 4 carried on a user's back is located on the back of a knapsack body 3, and the knapsack body 3 can be carried on a user's back by hooking the band 4 to the back. In this case, by bringing the back into contact with a dent part 7, a back bone is prevented from being brought into high pressure contact with a back plate part l and being ached. Casters 5 are mounted on a peripheral wall 2 positioned to the lower part of the knapsack body 3, and by rolling the casters, the knapsack can be carried as the casters are rolled. A rising and falling support leg 24 is located to the other end of a support frame 22, and by bringing the support leg 24 into a rise state, the knapsack body 3 can be erected. As noted above, various using ways can be provided to improve amenity.