Lifting machine on a piece processing line associable with a loading area suitable for receiving parts to be lifted and an unloading area, located higher up than the loading area, for unloading the pieces lifted by the machine, comprising: - translatable support means suitable for supporting at least one piece and for translating between a loading and unloading position in relation to the height of the loading area and the height of the unloading area, wherein the translatable support means consists in one translatable plate, positioned in a substantially vertical position; - an obstruction element at the unloading area suitable for obstructing the unloading or falling of pieces lifted by the translatable support means, to the unloading area wherein the obstruction element comprises one fixed plate, positioned in a substantially vertical position; - movement means suitable for moving the translatable support means; - control means suitable for controlling the movement means; - detection means, operatively connected to the control means, suitable for detecting the presence of lifted pieces in the unloading area and sending a detection signal to the control means, wherein the control means are programmed for controlling the movement means to move the translatable support means into the unloading position depending on the detection signal; and wherein the movement means are suitable for stopping the translatable support means in an intermediate position between the loading position and the unloading position respectively at a height between the height of the loading area and the height of the unloading area, in which falling of the pieces is prevented by the obstruction element; the lifting machine is characterized by the fact that movement means are suitable for stopping the translatable support means in an incipient unloading position, near the unloading area, last position in which a piece lifted by the translatable support means is prevented from falling into the unloading area by the obstruction element, on command of the control means when the detection means detect a condition of presence of mechanical pieces; and the movement means are suitable for resuming from said incipient unloading position the movement of the pieces depending on how said condition changes. - translatable support means suitable for supporting at least one piece and for translating between a loading and unloading position in relation to the height of the loading area and the height of the unloading area, wherein the translatable support means consists in one translatable plate, positioned in a substantially vertical position; - an obstruction element at the unloading area suitable for obstructing the unloading or falling of pieces lifted by the translatable support means, to the unloading area wherein the obstruction element comprises one fixed plate, positioned in a substantially vertical position; - movement means suitable for moving the translatable support means; - control means suitable for controlling the movement means; - detection means, operatively connected to the control means, suitable for detecting the presence of lifted pieces in the unloading area and sending a detection signal to the control means,