1. An estimation device comprising: a camera; a shape model setting unit configured for setting shape models showing three dimensional shapes of target objects whose shapes have individual differences; a feature point extracting unit configured for inputting an image sequence of a captured specific target object, the specific target object being one of the target objects, and extracting a plurality of feature points existing on the specific target object; and an object direction estimating unit configured for estimating a direction of the specific target object in accordance with the shape models which are set in the shape model setting unit and the feature points extracted in the feature point extracting unit, the shape model setting unit including: a storing unit configured for storing an average model showing an average shape of the target objects; a learning unit configured for learning an individual model showing a shape of the specific target object in accordance with a result of extracting in the feature point extracting unit; and a model switching unit configured for setting the average model stored in the storing unit as the shape model at a start of the device, and for setting the individual model as the shape model instead of the average model when a switching condition showing that the individual model learned in the learning unit becomes more reliable than the average model is satisfied.