PURPOSE: To hold a bucket at a desired angle to the ground by a method in which the angles of a boom, a bucket and vehicular body are obtained, and a tilt cylinder is controlled automatically on the basis of the detected angle signal of the boom and vehicular body so as to meet the target angle to the ground of the bucket.

CONSTITUTION: The first sensor 8 to detect before and behind inclined angles to the horizontal face is provided to a travelling vehicular body, and the second sensor 9 to detect the rocking angle of a boom 4 in relation to the vehicular body is provided to the pivotal support point of the boom 4. The third sensor 10 to detect the rocking angle of the bucket 5 in relation to the boom 4 is provided to the pivotal support point of the bucket 5. A tilt cylinder 6 is automatically controlled by a control mechanism 11 in such a way that detected angle by the third sensor 10 becomes a target set angle on the basis of detected angles by the first and second sensors 8 and 9. The angle to the ground of the bucket can be held regardless of the repetition of delivery and scooping and the pitching of machine body.