A data generation method for selecting one of the tread surface and the side wall surface of a tire as a surface to be measured and generating shape data used to evaluate a bulge/dent and a runout formed on the surface to be measured, comprising: a data acquiring step of scanning the surface to be measured using a shape sensor at a predetermined sampling period and acquiring height data items (D(i)) for one line extending in a circumferential direction, wherein the height data items (D(i)) for the one line form a data group including a plurality of height data items equal in number to the number of the sampling points; a candidate extraction step of providing a candidate extraction process to retrieve, from among the height data items (D(i)) for one line, a given number of consecutive height data items starting from a given sample point, calculate a difference (Δs) between the median (Med) of the retrieved height data items and each of the retrieved height data items, and extract, as candidates of a singular point, the sample points each having the difference (Δs) that is greater than or equal to a height threshold value and performing the candidate extraction process for the entire region of the height data items (D(i)) for one line while shifting the starting point; characterized by: an interpolation step of selecting (S109-S111) as singular points from among the candidates of a singular point, the candidates that satisfy a predetermined condition, in that if the number of consecutive candidates of a singular point is less than or equal to a threshold value, the consecutive candidates are determined to be singular points, removing the selected singular points from the height data items, interpolating the height data items (D(i)) at the removed singular points using the height data items at the sample points that are neighbors of the singular point and that are not singular points, and generating the shape data, wherein the height threshold value is a predetermined value that is greater than or equal to the product of the largest slope of a bulge/dent calculated from pre-generated model data representing the shape of a bulge/dent and half a width of the sampling zone corresponding to the given number of consecutive height data items. a data acquiring step of scanning the surface to be measured using a shape sensor at a predetermined sampling period and acquiring height data items (D(i)) for one line extending in a circumferential direction, wherein the height data items (D(i)) for the one line form a data group including a plurality of height data items equal in number to the number of the sampling points; a candidate extraction step of providing a candidate extraction process to retrieve, from among the height data items (D(i)) for one line, a given number of consecutive height data items starting from a given sample point, calculate a difference (Δs) between the median (Med) of the retrieved height data items and each of the retrieved height data items, and extract, as candidates of a singular point, the sample points each having the difference (Δs) that is greater than or equal to a height threshold value and performing the candidate extraction process for the entire region of the height data items (D(i)) for one line while shifting the starting point; characterized by: an interpolation step of selecting (S109-S111) as singular points from among the candidates of a singular point, the candidates that satisfy a predetermined condition, in that if the number of consecutive candidates of a singular point is less than or equal to a threshold value, the consecutive candidates are determined to be singular points, removing the selected singular points from the height data items, interpolating the height data items (D(i)) at the removed singular points using the height data items at the sample points that are neighbors of the singular point and that are not singular points, and generating the shape data, wherein the height threshold value is a predetermined value that is greater than or equal to the product of the largest slope of a bulge/dent calculated from pre-generated model data representing the shape of a bulge/dent and half a width of the sampling zone corresponding to the given number of consecutive height data items. an interpolation step of selecting (S109-S111) as singular points from among the candidates of a singular point, the candidates that satisfy a predetermined condition, in that if the number of consecutive candidates of a singular point is less than or equal to a threshold value, the consecutive candidates are determined to be singular points, removing the selected singular points from the height data items, interpolating the height data items (D(i)) at the removed singular points using the height data items at the sample points that are neighbors of the singular point and that are not singular points, and generating the shape data, wherein the height threshold value is a predetermined value that is greater than or equal to the product of the largest slope of a bulge/dent calculated from pre-generated model data representing the shape of a bulge/dent and half a width of the sampling zone corresponding to the given number of consecutive height data items.