Abstract: A flooring material is composed by interpositioning at least one intermediate layer (2), in the form of a sheet that is weakly adhered to a sheet base material (1) to an extent that at least its upper surface can be easily peeled from said sheet base material (1), within said sheet base material corresponding to the bottoms of wiring grooves (6 and 7) formed in said sheet base material (1). A plurality of cuts are made along cut lines (4 and 5) of said flooring material at a depth that extends to the above-mentioned intermediate layer (2) at prescribed intervals. Wiring grooves (6 and 7) are formed by peeling off portions (1a and 1b) of the sheet base material (1) within said cut lines to enable wiring along said grooves (6 and 7).