An object is to provide an articulated object position and posture estimation device with reduced calculation cost of model fitting for estimating position and posture and with improved estimation speed. A posture model storage section 2 stores data concerning to a posture model with low-dimensional parameters under movement restraint. The low-dimensional parameters are obtained by performing a principal component analysis on time-series postures of an articulated object frame model corresponding to a predetermined limited movement of an articulated object such as human body. A human body position and posture estimation device 101 generates a image of each posture of the articulated object frame model within postures which can be taken by the posture model in a human body model image generating section 4, performs a matching with an estimation target articulated object image in a position and posture estimation section 10, and thus, estimates a posture.