To provide a knapsack equipped with a structure by which the shaking of articles or the like being housed can easily be prevented from occurring when necessary even when a user performs exercises such as walking or running.

This knapsack has a bag body 12 which has a plurality of housing sections 12a, 12b and 12c for housing loads, and in which a back surface 14 being confronted with the back of the user is formed on the external surface. The knapsack is equipped with a shoulder belt 20 which is attached to the bag body 12, and comes into contact with the shoulder of the user, and a waist belt 26 which comes into contact with the hip of the user. In the plurality of housing sections 12a, 12b and 12c, a through-hole 18 which penetrates in the side surface direction of the bag body 12 is provided on one partitioning section which is in parallel with the back surface 14. The waist belt 26 is made to pass through the through-hole 18, and both end sections 26b protrude from both sides of the opening section.