To make assembling easy, make a knockdown fire prevention fence strong in impact and make it a fire prevention fence having no fear of rusting by forming it of a foundation forming a projection part on the upper face and a fence panel providing a recess part on the lower face.

Mortar 13 is laid on the foundation 11, the fence panel 4 is hung up, and the recess part 5 of the fence panel 4 is positioned on the anchor bolt of the foundation 11. Next, the fence panel 4 is lowered to be erected on the foundation 11. The mortar is applied on the side of the fence panel 4, and the next panel 4 is hung up to be similarly successively erected. Successively, mortar 14 is injected from the mortar injection hole 6 of the panel 4. As the result, the air of the inside of the recess part 5 is made to flow out of an air vent hole 7, finally, the mortar 14 is made to flow out of the air vent hole 7, and filled into the inside of the recess part 5. Thereby the foundation 11 is placed in parallel with the manufacture of the fence panel 4, since the projection part of the foundation 11 is inserted in the recess part 5 of the panel 4 and mortar is made to flow to manufacture the fire prevention fence, a construction period is shortened and a cost can be reduced.