PURPOSE: To provide excellent sound proofing properties, moreover wooden corrugated sheets each and their both sides wooden flat plate forming a intermediate layer hard to corrode and even the manufacturing process is simple.

CONSTITUTION: In an architectural panel which is comprised by a method wherein a plurality of wooden corrugated sheets 1 having stripelike recessed parts and projected parts alternatively on both sides are laminated and stuck to each other so that the recessed parts and projected parts are not fitted in each other, an intermediate layer 3 possessing a large number of hollow parts are formed and wooden plane sheet 4 is laminated and stuck to both the sides of the intermediate layer 3, a sound insulation sheet 5 which is comprised by allowing a substance having a high specific gravity in a flexible synthetic resin sheet is interposed and laminated. In this case, the same sound insulation sheet 5 may be interposed or laminated between the wooden corrugated sheet 1 of an intermediate layer 3.