PROBLEM TO BE SOLVED: To provide a raw material storage hopper in which raw material can be prevented from entangling in a discharge screw conveyer and bridging between blocks of the raw material can be prevented.SOLUTION: A raw material storage hopper 1 is provided that comprises: a hopper main body 5; a raw material inlet part 4 formed by opening the top surface of the hopper main body 5; a discharge screw conveyer 6 provided in the bottom of the hopper main body 5; and a raw material outlet part 7 provided at the transportation terminal side of the screw conveyer 6. A backward conveyance screw conveyer 25 conveying the raw material in a direction opposite to the conveying direction of the discharge screw conveyer 6 is placed in the hopper main body 5 to loosen the charged raw material.SELECTED DRAWING: Figure 2【課題】排出用のスクリューコンベアへの原料の絡み付きを防止するとともに、原料の塊どうしのブリッジを防止することのできる原料貯留用ホッパを提供する。【解決手段】ホッパ本体5と、ホッパ本体5上面を開口した原料入口部4と、ホッパ本体5底部に設ける排出用のスクリューコンベア6と、スクリューコンベア6の搬送終端側に設けた原料出口部7と、を備えた原料貯留用ホッパ1において、ホッパ本体5内には、投入された原料をほぐすために、排出用のスクリューコンベア6の搬送方向とは逆方向に搬送する逆送スクリューコンベア25を配設した。【選択図】図2