A deformable sensor system that can be used for pressure-distribution sensors. The deformable sensor system makes it possible to obtain a pressure distribution with a much higher accuracy, while reducing the number of electrodes. The system utilizes a deformable sensor which can detect deformation as the electric resistivity of the surface increases monotonically as an elastic deformation variation in each of the elastic deformations increases. Based on a voltage being detected by means of a detecting unit, the deformable sensor electric-resistivity variation computing unit computes the variation of the electric resistivity based on the method of least squares with a restriction condition imposed thereon. The system uses such a technology as “EIT” that is based on an inverse-problem theory. At an external-force position computing unit, a position in a pressure-receiving surface, position which receives an external force, is computed based on the computed electric-resistivity variation.