An information processing apparatus configured to estimate a position and orientation of a measuring object using an imaging apparatus (20, 30) mounted on an end tip of a robot arm, the information processing apparatus comprising: three-dimensional shape model storing means configured to store data of a three-dimensional shape model of the measuring object; image input means configured to acquire a captured image of the measuring object, captured by the imaging apparatus at a first time; position and orientation input means configured to input a relative position and orientation between the imaging apparatus and the measuring object; first position and orientation updating means configured to update the position and orientation by matching the three-dimensional shape model to the image, using the position and orientation input by the position and orientation input means; obtaining means configured to obtain from a control module of the robot arm the position and orientation of the imaging apparatus at both the first time and a second, different time after which the imaging apparatus (20, 30) has moved, based on the position and orientation of the end tip of the robot arm; position and orientation difference information input means configured to acquire a position and orientation difference amount of the imaging apparatus relative to the measuring object between the first time and the second time, based on the position and orientation of the imaging apparatus obtained by the obtaining means; and second position and orientation updating means configured to update the position and orientation based on the position and orientation difference amount, using the position and orientation updated by the first position and orientation updating means. three-dimensional shape model storing means configured to store data of a three-dimensional shape model of the measuring object; image input means configured to acquire a captured image of the measuring object, captured by the imaging apparatus at a first time; position and orientation input means configured to input a relative position and orientation between the imaging apparatus and the measuring object; first position and orientation updating means configured to update the position and orientation by matching the three-dimensional shape model to the image, using the position and orientation input by the position and orientation input means; obtaining means configured to obtain from a control module of the robot arm the position and orientation of the imaging apparatus at both the first time and a second, different time after which the imaging apparatus (20, 30) has moved, based on the position and orientation of the end tip of the robot arm; position and orientation difference information input means configured to acquire a position and orientation difference amount of the imaging apparatus relative to the measuring object between the first time and the second time, based on the position and orientation of the imaging apparatus obtained by the obtaining means; and second position and orientation updating means configured to update the position and orientation based on the position and orientation difference amount, using the position and orientation updated by the first position and orientation updating means.