A plastic working device for workpiece material, comprising: - a first mold having a groove which retains a workpiece material and which is formed at least partly into a generally linear shape; - a second mold which has a first guide portion to be relatively movably fitted to the groove, and which has a body portion having a through hole intersecting and communicating with the groove; - a first relative movement unit for moving the first mold and the second mold relative to each other so that the workpiece material substantially immovably retained in the groove of the first mold is pushed from the groove into the through hole; - a retainer unit for retaining a state that the first guide portion is fitted to the groove of the first mold; characterised by: - a third mold having a groove adapted to retain the workpiece material and which intersects and communicates with the through hole and moreover which is formed at least partly into a generally linear shape, wherein - the second mold has a second guide portion adapted to be relatively movably fitted to the groove of the third mold; and further comprising - a second relative movement unit for moving the second mold and the third mold relative to each other, wherein - the retainer unit is adapted to retain a state that the second guide portion is fitted to the groove of the third mold. - a first mold having a groove which retains a workpiece material and which is formed at least partly into a generally linear shape; - a second mold which has a first guide portion to be relatively movably fitted to the groove, and which has a body portion having a through hole intersecting and communicating with the groove; - a first relative movement unit for moving the first mold and the second mold relative to each other so that the workpiece material substantially immovably retained in the groove of the first mold is pushed from the groove into the through hole; - a retainer unit for retaining a state that the first guide portion is fitted to the groove of the first mold; characterised by: - a third mold having a groove adapted to retain the workpiece material and which intersects and communicates with the through hole and moreover which is formed at least partly into a generally linear shape, wherein - the second mold has a second guide portion adapted to be relatively movably fitted to the groove of the third mold; and further comprising - a second relative movement unit for moving the second mold and the third mold relative to each other, wherein - the retainer unit is adapted to retain a state that the second guide portion is fitted to the groove of the third mold. - a third mold having a groove adapted to retain the workpiece material and which intersects and communicates with the through hole and moreover which is formed at least partly into a generally linear shape, wherein - the second mold has a second guide portion adapted to be relatively movably fitted to the groove of the third mold; and further comprising - a second relative movement unit for moving the second mold and the third mold relative to each other, wherein - the retainer unit is adapted to retain a state that the second guide portion is fitted to the groove of the third mold.