1. A method of supporting an optimum wiring design of a linear structure by a computer, such that the computer performs the steps comprising: providing by the computer, a finite element model which corresponds to both of the linear structure and a support member which supports the linear structure, the finite element model being formed as an elastic body having a plurality of combined beam elements which retain linearity; setting physical properties and restriction conditions of the linear structure and the support member to the finite element model; calculating a predictive shape of the finite element model which is in a physically balanced condition based on the physical properties and the restriction conditions; and outputting a calculation result of the calculation process; wherein the support member is a complete restriction type support member; wherein a complete restriction is applied to a joint corresponding to a center axis of the support member as one of the restriction conditions; and wherein a complete freedom is applied to a joint corresponding to other than the center axis of the support member as one of the restriction conditions; the method further comprising: calculating an inclination of the support member with respect to a predetermined reference line on the basis of the joint corresponding to the center axis of the support member and joints corresponding to two end portions of the support member, wherein the outputting process outputs the inclination of the support member along with the calculation result.