A machining device comprising a machining device unit and a loading device for loading workpieces into a holder disposed in a housing of the machining device unit through a first access hole for transfer formed in the housing of the machining device unit, the loading device comprising: a storage stand for storing a plurality of workpieces in such a manner that the workpieces are arranged vertically, the storage stand being disposed outside the housing of the machining device unit, the storage stand having a plurality of hold shelves each of which being able to store one workpiece, wherein said hold shelves are disposed vertically in the storage stand and divided into an upper group and a lower group, where the distance between the lowermost hold shelf in the upper group and the uppermost hold shelf in the lower group is larger than the distances between other adjacent hold shelves; a transfer device; an elevator for carrying the transfer device up and down at a side of the storage stand outside the housing of the machining device unit; and a housing disposed adjacent to the housing of the machining device unit, wherein the storage stand, the transfer device, and the elevator are disposed in the housing of the loading device, and a second access hole for transfer is formed in the housing of the loading device, the second access hole for transfer being communicated with the first access hole for transfer formed in the housing of the machining device unit, and a position of the second access hole for transfer in the housing of the loading device is determined between the lowermost hold shelf in the upper group and the uppermost hold shelf in the lower group of the storage stand, wherein, the elevator is configured to move the transfer device to a level of a certain workpiece of the plurality of workpieces and the transfer device is configured to pull out the workpiece from the storage stand; and the elevator is configured to move the transfer device to a level of the first and second access holes for transfer (12a, 53a) and the transfer device is configured to load the workpiece into the holder through the first and second access holes for transfer (12a, 53a), wherein the elevator is configured to carry the transfer device at a location for elevation opposite to the first access hole for transfer relative to the storage stand; and the transfer device is configured to pull out the workpiece from the storage stand to the location for elevation, and the transfer device is configured to load the workpiece into the holder after transferring the workpiece from the location for elevation to the holder between the lowermost hold shelf in the upper group and the uppermost hold shelf in the lower group of the storage stand and the first and second access holes for transfer (12a, 53a). a storage stand for storing a plurality of workpieces in such a manner that the workpieces are arranged vertically, the storage stand being disposed outside the housing of the machining device unit, the storage stand having a plurality of hold shelves each of which being able to store one workpiece, wherein said hold shelves are disposed vertically in the storage stand and divided into an upper group and a lower group, where the distance between the lowermost hold shelf in the upper group and the uppermost hold shelf in the lower group is larger than the distances between other adjacent hold shelves; a transfer device; an elevator for carrying the transfer device up and down at a side of the storage stand outside the housing of the machining device unit; and a housing disposed adjacent to the housing of the machining device unit, wherein the storage stand, the transfer device, and the elevator are disposed in the housing of the loading device, and a second access hole for transfer is formed in the housing of the loading device, the second access hole for transfer being communicated with the first access hole for transfer formed in the housing of the machining device unit, and a position of the second access hole for transfer in the housing of the loading device is determined between the lowermost hold shelf in the upper group and the uppermost hold shelf in the lower group of the storage stand, wherein, the elevator is configured to move the transfer device to a level of a certain workpiece of the plurality of workpieces and the transfer device is configured to pull out the workpiece from the storage stand; and the elevator is configured to move the transfer device to a level of the first and second access holes for transfer (12a, 53a) and the transfer device is configured to load the workpiece into the holder through the first and second access holes for transfer (12a, 53a), wherein the elevator is configured to carry the transfer device at a location for elevation opposite to the first access hole for transfer relative to the storage stand; and the transfer device is configured to pull out the workpiece from the storage stand to the location for elevation, and the transfer device is configured to load the workpiece into the holder after transferring the workpiece from the location for elevation to the holder between the lowermost hold shelf in the upper group and the uppermost hold shelf in the lower group of the storage stand and the first and second access holes for transfer (12a, 53a).