PURPOSE: To obtain comfortable feeling when a mat is stepped on with shoes, and prevent a fall accident from being generated at the time of slipping with water by arranging a plurality of tongue-shaped swelling sections on the whole surface, and by arranging spaces opening on the lower surfaces of the mat, at the lower sections of the respective swelling sections, to make uniform the thickness of the whole body of the mat.

CONSTITUTION: A plurality of endless monofilaments 1 are piled up respectively to required thicknesses in the shapes of loops at random, and the monofilaments to be piled up are jointed to each other to be fusion-welded at a high temperature when they are spun from a spinning pack, and a mat M is composed. In this case, on the whole body of the mat M, a plurality of tongue-shaped swelling sections 2 are arranged, and a rugged surface is contrived to be formed with the whole surface, and with the lower sections of these respective swelling sections 2, tongue-shaped spaces 3 opening on the lower surface are confronted, and the whole body of the mat is contrived to be formed to a uniform thickness. Besides, the surfaces to be jointed to each other, of the respective monofilaments 1 are firmly jointed to each other with adhesives, and are composed, and by mixing colored filaments 1a by a proper quantity in the shapes of the loops at random in the same manner as the respective monofilaments 1, the filaments excellent in color can be presented.