PROBLEM TO BE SOLVED: To provide a diffuser that is compatible with a vertical motion of a harvester.SOLUTION: A forage crop inlet port 40 of a hopper 4 is directed forward and longitudinally faced to a forage crop outlet 31A set so that a discharge direction of a forage crop B becomes backward. Also, a diffuser 4A included in the hopper 4 is formed as a length contacted with the input forage crop B, irrespective of a change of position in the vertical direction of the forage crop outlet 31A due to the vertical motion of a chute 3A accompanying the vertical motion of a harvester 3.
