PROBLEM TO BE SOLVED: To provide a fixing method of a base material to a wall surface with which the base material can be firmly, easily and surely mounted even when the wall surface is made of a weak material such as a gypsum board, and a Nageshi (a horizontal piece of timber to connect pillars) rail as furniture for improving the appearance.SOLUTION: A base material 1 to be a foundation of mounting to a wall surface W is formed in a band plate shape by extrusion molding of aluminum or the like, a ridged inflection rib 7 formed from an upper inclined wall 7a and a lower inclined wall 7b is provided thereon in a projective manner and on an inner surface of the upper inclined wall, an inner protrusion 13 is provided in a projective manner in parallel with the lower inclined wall, thereby providing an inclined narrow groove 20 to be a guide for passing a pin between the lower inclined wall and the inner protrusion. On the upper inclined wall, a pair of right and left pin holes 17 are opened for passing the pin
