1. A position/orientation measurement apparatus for measuring a position/orientation of a measurement object, characterized by comprising: input means for inputting a two-dimensional image of the measurement object captured by an image capturing apparatus; obtaining means for obtaining distance data of the measurement object measured by a distance sensor; detection means for detecting an image feature of the measurement object from the two-dimensional image; determination means for determining a state of the measurement object; mode setting means for setting, based on the state determined by said determination means, a usage mode regarding the image feature and the distance data when measuring the position/orientation; and measurement means for measuring the position/orientation of the measurement object in accordance with the usage mode set by said mode setting means.