According to the present invention, a shaking separator plate 26 has attached thereto: a shielding plate 192 that hangs above a front part of a second conveyor mechanism 31 in an orientation extending from a first grain flow plate 191; and a guide rail 196 elongated to the right and left in front of the shielding plate 192. The rear end side of a grain sieve 176 is supported by the guide rail 196. The front end side of the grain sieve 176 is coupled to the rear end side of a grain pan 173.
