PURPOSE: To provide a hopper having a bridging preventing function wherein a bridging phenomenon is prevented from occurring during the discharge of stored matters.

CONSTITUTION: A hoppor body 1 is provided, wherein at least one of opposing side walls 5, 6 is inwardly inclined and a feed port 3 is provided at the upper part of the body 1 so as to be offset toward the side of either of the inclined walls and a discharge port 4 is provided at the bottom so as to be throttled. A movable wall 7 is provided in the hopper body 1 so as to be oscillated between the inclined side walls 5, 6 in such a manner that the wall 7 is pivotally supported by the hopper body 1 at the upper end thereof so as to be oscillated by the pressure of stored matters, and when the wall 7 oscillates toward any one of the side walls, an upper opening and a lower opening, which are formed between the wall 7 and one of the walls 5, 6, are set so that the lower opening becomes larger than the upper opening.