PURPOSE: To provide the positioning jig which can easily join panels in such a way as to be flush with each other in a joining section of architectural panels consisting of a dwelling house.

CONSTITUTION: When floor panels 10a and 10b where surface members 14a and 14b are stuck on the single surface of each rectangular core member 12a and 12b, are connected to each other so as to allow a floor to be constructed, the jig is provided with a slide bar 20 which is installed onto an installation hole 32 formed in the core member 12a of the floor panel 10a on the protruded side in the thickness direction, and with a center block 22 which is disposed at the lower surface side of each adjacent core member 12a and 12b, and supports the slide bar 20 in such a way that it can fix the slide bar at the one end side of the center block. And the jig is also provided with a cam block 24 which is installed on the other end side rotatably around its shaft, abuts against the lower surface of the core member 12b of the floor panel 10b at the recessed side in the thickness direction for pressing the aforesaid lower surface, and with a lever 26 which is installed on the cam block 24 for rotating the cam block 24.