Understanding of consumer behavior contributes a store for improving the profitability. It is important to analyze and understand consumer trajectories in a store building for the purpose. Therefore analyses of purchasing history and consumer's movement are performed in the process. Purchasing histories is regularly obtained via a POS system. For acquiring the movement path, a measurement device using an optical sensor and a gyro sensor was proposed. However, the device has a problem of poor measurement accuracy because of the accumulated error in the sensors. In this study, we propose a method for improving the accuracy by using a particle filter and an environmental map. We describe the outline of the device and the path estimated by the method from the measured data with a map.