To provide a backpack that is hardly hard on the shoulders, hip, etc., even if it is carried on the back for hours.

The backpack 1 has a protruding part 21 that is vertically raised in the middle part in the width direction of an upper part of a back pad 2. Moreover, a staged part 22 that is raised stepwise laterally in the middle part in the height direction of the back pad 2 can also be provided. As a concrete embodiment of the backpack 1, it is preferred that the protruding part 21 that is raised in an oblong rectangular shape, with a trapezoidal cross-sectional shape, is formed in the middle part in the width direction in an upper half part of the back pad 2 and a deformed pentagonal shape with the upper side being an oblique line extending laterally is raised in a lower half part of the back pad 2 to form the staged part 22.