To provide a clamp transfer device for parallel materials saving space in a planar arrangement by spatially stacking a clamp mechanism for the parallel materials and a lifter for stacking the parallel materials.

The clamp mechanism 20 is arranged on a position above a material clamp lower guide 19 supporting the parallel materials b, in a manner to move vertically. An upper edge of an arcuate guide plate 29 in the material clamp lower guide 19 is formed into a circular arc edge 29a that is high at the center, and a lower edge of material clamp upper guide 36 equipped to the clamp mechanism 20 is formed into a circular arc recessed edge 36a, so that the parallel materials b clamped by the clamp mechanism 20 become an arch shape. The material clamp lower guide 19 moves around between a material clamp position directly under the clamp mechanism 20 where the lower guide stops, and retraction position to which the lower guide retracts outward from the planar area of the parallel materials b with respect to the material clamp position.