1. A response surface modeling device, in which a plurality of samples, which are coordinate values composed of a plurality of factor values serving as a source to drive a target for measurement, and of a response value calculated as a result of driving, are placed in a plurality of spaces; a linear model, which serves as a face approximating to the plurality of samples thus placed, is created; the linear model is partitioned based on distribution of the samples; and a response surface model, which is composed of a plurality of linear models created based on the samples belonging to a region formed by the partition, is created, the response surface modeling device comprising: an input unit that inputs the samples; a sample placement unit that places the samples in the spaces, the samples being input by way of the input unit; a linear modeling unit that creates the linear model for each region, based on coordinate values of the samples belonging to the region; a region partition unit that partitions the linear model, based on the samples belonging to the region; a partition region determination unit that determines whether it is possible to partition the region, based on a number of the factor values and placement of the samples belonging to the region to be partitioned; and a modeling unit that creates a response surface model by placing each linear model in the spaces, when the partition region determination unit has determined that partition is impossible in all the regions.