PURPOSE: To sufficiently remove even highly sticky soil and sand by a method in which a soil discharge plate covering the opening of the bottom plate of a bucket is rotatably supported on the front edge of the bucket, and the other end of the soil discharge plate and the tip of an arm are connected with each other by a rope.

CONSTITUTION: An opening 14 is provided in the bottom plate 15 of a bucket 9, one end of a soil discharge plate 11 covering the opening is rotatably attached to the front edge of the bottom plate 15, and the other end of the plate 11 is connected with an arm 1 by a rope 13. A guider for the rope 13 is provided below the tip of the arm 1. When moving the bucket 9 to its soil discharging attitude by shrinking a bucket cylinder 10, the plate 11 is rocked by the actions of the rope 13 and the rope guider 17 and thereby excavated soil in the bucket is discharged.