A groove inclined path for diagonally downwardly delivering hydrogenated petroleum resin pellets loaded through a loading port is provided in a storage hopper for storing the hydrogenated petroleum resin pellets. The groove inclined path is defined by a plurality of groove-inclined-path members each having an inclined plate and side plates to define a groove structure, the groove-inclined-path members being vertically disposed so that flow directions of the hydrogenated petroleum resin pellets become opposite. The vertically adjacent ones of the groove-inclined-path members are disposed so that the hydrogenated petroleum resin pellets dropped from upper one of the groove-inclined-path members are brought into contact with the plate member of immediately lower one of the groove-inclined-path members to reverse a flow direction thereof, thereby reducing a flow speed of the hydrogenated petroleum resin pellets.