A work machine which performs a holding task of holding an object of a work, a carrying task of carrying the object being held to a position above a destination, and a discharge task of discharging the object at the position above the destination, the work machine comprising: a working device which includes an attachment for holding the object; a load acquisition section which acquires a load of the object held by the attachment; and an estimative load determination part which determines, based on the load acquired by the load acquisition section, an estimative load of the object estimated to be discharged at the position above the destination in the discharge task when a predetermined estimative load determinative criterion is satisfied, characterized by an estimative load update part which updates, based on the load acquired by the load acquisition section after the estimative load is determined, the estimative load when a predetermined estimative load update criterion is satisfied; a definitive load determination part which determines, when a predetermined definitive load determinative criterion for determining a definitive load of the object to be actually discharged at the position above the destination in the discharge task is satisfied, the estimative load as the definitive load, wherein the estimative load determinative criterion includes at least one of a criterion that a predetermined first reduction manipulation is detected in the holding task and a criterion that the first reduction manipulation is detected after the holding task, the first reduction manipulation being for reducing an amount of the object held by the attachment, the estimative load update criterion includes a criterion that a predetermined second reduction manipulation is detected after the estimative load is determined, the second reduction manipulation being for reducing an amount of the object held by the attachment after a completion of the first reduction manipulation, the definitive load determinative criterion includes a criterion that the load acquired by the load acquisition section after the estimative load is determined is equal to or smaller than a predetermined load threshold, and the estimative load update criterion further includes a criterion that a time from the completion of the first reduction manipulation to a start of the second reduction manipulation is equal to or longer than a predetermined time threshold. a working device which includes an attachment for holding the object; a load acquisition section which acquires a load of the object held by the attachment; and an estimative load determination part which determines, based on the load acquired by the load acquisition section, an estimative load of the object estimated to be discharged at the position above the destination in the discharge task when a predetermined estimative load determinative criterion is satisfied, characterized by an estimative load update part which updates, based on the load acquired by the load acquisition section after the estimative load is determined, the estimative load when a predetermined estimative load update criterion is satisfied; a definitive load determination part which determines, when a predetermined definitive load determinative criterion for determining a definitive load of the object to be actually discharged at the position above the destination in the discharge task is satisfied, the estimative load as the definitive load, wherein the estimative load determinative criterion includes at least one of a criterion that a predetermined first reduction manipulation is detected in the holding task and a criterion that the first reduction manipulation is detected after the holding task, the first reduction manipulation being for reducing an amount of the object held by the attachment, the estimative load update criterion includes a criterion that a predetermined second reduction manipulation is detected after the estimative load is determined, the second reduction manipulation being for reducing an amount of the object held by the attachment after a completion of the first reduction manipulation, the definitive load determinative criterion includes a criterion that the load acquired by the load acquisition section after the estimative load is determined is equal to or smaller than a predetermined load threshold, and the estimative load update criterion further includes a criterion that a time from the completion of the first reduction manipulation to a start of the second reduction manipulation is equal to or longer than a predetermined time threshold.