To make a protective fence and a concrete form lightweight and easy to handle by forming a pair of divided bodies by bisecting a bottomed hollow member whose main material is a synthetic resin in the depth direction and making them connectable and separable.

A pair of divided bodies 10, 20 are formed by bisecting a bottomed hollow member A made of a synthetic resin containing glass fibers at the center in the depth direction. The flange parts 11, 21 of the seams 12, 22 of the bisected bodies 10, 20 are made connectable and separable by tightening with a bolt and a nut 30. A vertical rib 51 and a horizontal rib 52 are provided integrally in a lattice form to increase rigidity. The bottomed hollow member A has a wall forming part 2, a skirt part 3 and a pedestal part 4. An anchor 7 is driven into the bottom 3b of the depression 3a of the skirt part 3 so that it may be fixed to a road surface. After fixed to the road surface, a solid is filled in the bottomed hollow member A. To manufacture a concrete media strip unit, the bottomed hollow member A and the form are used, and concrete is placed and separated after set.