Sandwich PUF panel with a concealed-fixing method for high quality industrial and commercial buildings, where good aesthetics are paramount. The special double labyrinth joint of this panel, provides mechanical resistance and insulation superior to any other wall panel product of this kind. The panel external micro-V increases the aesthetic appeal of this panel, which can be orientated both vertically and horizontally as required. If wind pressure on a wall sandwich panel is more than allowed limit of panels so it is needed to fix the sandwich panels with self-drilling screws on a metal net. On the ordinary panels these screws are visible but hidden screw wall panel are designed so that the drilling screw are operated under the notch and tab and cause tight and firm connection. Alfa hidden screw wall panels can be manufactured with various patterns and designed like fine, corrugated coarse corrugated. Beside the designs Alfa is presenting the hidden screw wall panel with water fall design to the market that has great insulator and firmness and can be assembled horizontally and vertically as well.