Disclosed is a position estimation device including a feature extraction unit that extracts invariant features from an input image, a matching unit that obtains matching between an input image and a registered place by referring to a database containing each registered place and invariant features in association, a similarity calculation unit that calculates a similarity with inclusion of a registered place near a selected registered place when the matching is a threshold or more, and a position identification unit that identifies the input image as a registered place when the similarity is a threshold or more. The feature extraction unit extracts local features from each input image being sequential images taken sequentially, selects features matched between the sequential images as sequential features, and calculates invariant features based on the sequential features. The number of sequential images is variable depending on the number of matched features.