PURPOSE: To increase production efficiency of a panel, by sucessively dropping set by set panel frame materials in a temporarily framed state onto a slat conveyor and feeding out the material to the next process.

CONSTITUTION: A panel frame material 2 is dropped down on a slat conveyor A and held to a temporarily framed state by positioning elements 3. Secondly, a vertical holding plate 9 of L-shaped holding means of the first frame material holding means C is moved backward, and plural sets of panel frame materials 2', 2" are dropped while being guided by a temporarily framing jig B, then the panel frame material 2' located to the lowermost part is received by an L-shaped holding plate 7 and held. Repeating this process, the panel frame materials 2', 2" are successively dropped set by set onto the slat conveyor A in a temporarily framed state and fed out to the next process, thus production efficiency of the panel can be increased.