1. A geometry simplification apparatus comprising: an extraction unit configured to extract at least one additional feature in a geometry from a part, the at least one additional feature similar to a first feature in the geometry from the part for which geometry simplification has already been manually performed to simplify the first feature, wherein the extraction unit is configured to extract the at least one additional feature based on information about a selection order and a simplification method of the simplified first feature and to extract a feature targeted for simplification from the at least one additional feature; and a simplification unit configured to simplify the feature targeted for simplification extracted by the extraction unit based on information about a geometry simplification method performed to the first feature.