1. A geometry simplification apparatus comprising: an extraction unit configured to extract a simplification target place of a component; a first determination unit configured to determine whether another component is in contact with the simplification target place; a simplification unit configured to simplify the-geometry of the simplification target place; a second determination unit configured to determine whether another component is in contact with the simplification target place of which the geometry is simplified by the simplification unit; a comparison unit configured to compare contact relationship between another component and the simplification target place before and after the geometry of the simplification target place is simplified based on the determination results of the first and second determination units; and a correction unit configured to correct the geometry of the component in which the geometry of the simplification target place is simplified by the simplification unit to a different geometry which does not interfere with another component while keeping the initial contact relationship between another component and the component before the geometry of the simplification target place is simplified by the simplification unit according to comparison results by the comparison unit.