To alleviate a load to a weight sensor by simplifying a structure.

A bearing support plate 25 and a motor 30 are fixed to a lower portion of a support frame 24 supported to one end side of a load cell 23, and a shutter support 45 is turnably supported to the plate 25 at a shaft 46 as a center. A shutter plate 55 is detachably supported to one end side of the support 45, and a hopper body 60 is detachably supported to a hopper locking plate 43 provided at the support 25. An arm 32 is fixed to a rotary shaft 31 of the motor 30, and a roller 34 at an end of the arm 32 is engaged with a long hole 49 extended to the other end side of the support 45. The plate 55 supported to the support 45 closes a lower portion opening surface of the body 60 at a position where the arm 32 is perpendicularly crossed with the hole 49 of the support 45, and when the arm 32 is rotated from this position, a lower portion opening surface of the body 50 is opened.