To provide a deformable sensor system, which makes it possible to obtain a pressure distribution with a much higher accuracy, while reducing the number of electrodes.A deformable sensor 12 comprises an elastic material whose electric resistivity, when all types of elastic deformations are caused therein respectively, 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 22, the deformable sensor 12's electric-resistivity variation δρ(x, y), which minimizes an evaluation Function J of Equation (1) while satisfying a condition of Equation (2), is computed at an electric-resistivity variation computing unit 25 using such a technology as “EIT” that is based on an inverse-problem theory. At an external-force position computing unit 26, a position in a pressure-receiving surface 12a, position which receives an external force, is computed based on the computed electric-resistivity variation δρ(x, y). J=∥δV(m,n)−Sm,n,x,y·δρ(x,y)∥2  (1) However, δρ(x,y)≧0  (2)