Abstract: An apparatus (2) for transferring wafers between carriers of different densities having a loading station and unloading station; a lift for raising the wafers to be transferred into a wafer handler secured to a support. The wafer handler has two substantially cylindrical arms, cantilevered from the support with each arm provided with slotted rollers for holding and guiding wafers inserted therein. The arms are rotatable in four steps of 90 degrees each to cause the rollers to each take four different positions. A first position is for placing a first set of wafers in selected slots in the rollers, a second for holding the first set of wafers and passing a second set of wafers into a different set of slots interdigitated with the first set of wafers, a third position for holding the first and the second sets of wafers, and a fourth for transferring both sets of wafers into a new carrier. The apparatus can vary the sequence of loading and unloading and is suitable for use in automatic wafer production lines.