A head mounted display apparatus including a display unit for transmissively visually recognising an outside world, the head mounted display apparatus comprising: a motion sensor ; an RGB sensor and a depth sensor ; a memory ; and a processor configured to: allow the display unit to display a predetermined image in correspondence with a position of a subject in the outside world transmissively visually recognized; acquire view range movement information representing a motion of the display unit using the motion sensor ; and acquire subject movement information representing a relative motion of the subject to the display unit using the RGB sensor and the depth sensor , and store and update a three-dimensional trajectory data of the subject stored in the memory based on the acquired subject movement information, wherein the processor is further configured to, when the acquired view range movement information and the acquired subject movement information are substantially not matched, estimate a movement velocity of the subject using an estimation theory based on the three-dimensional trajectory data of the subject stored in the memory, estimate a relative position of the subject to the display unit using the estimated movement velocity of the subject, and determine a display position of the predetermined image based on the estimated relative position; wherein the view range movement information and the subject movement information are substantially matched when the motion of the display unit represented by the view range movement information and the relative motion of the subject to the display unit represented by the subject movement information are in opposite directions and the differences in magnitude are within a threshold value. a motion sensor ; an RGB sensor and a depth sensor ; a memory ; and a processor configured to: allow the display unit to display a predetermined image in correspondence with a position of a subject in the outside world transmissively visually recognized; acquire view range movement information representing a motion of the display unit using the motion sensor ; and acquire subject movement information representing a relative motion of the subject to the display unit using the RGB sensor and the depth sensor , and store and update a three-dimensional trajectory data of the subject stored in the memory based on the acquired subject movement information, allow the display unit to display a predetermined image in correspondence with a position of a subject in the outside world transmissively visually recognized; acquire view range movement information representing a motion of the display unit using the motion sensor ; and acquire subject movement information representing a relative motion of the subject to the display unit using the RGB sensor and the depth sensor , and store and update a three-dimensional trajectory data of the subject stored in the memory based on the acquired subject movement information, wherein the processor is further configured to, when the acquired view range movement information and the acquired subject movement information are substantially not matched, estimate a movement velocity of the subject using an estimation theory based on the three-dimensional trajectory data of the subject stored in the memory, estimate a relative position of the subject to the display unit using the estimated movement velocity of the subject, and determine a display position of the predetermined image based on the estimated relative position; wherein the view range movement information and the subject movement information are substantially matched when the motion of the display unit represented by the view range movement information and the relative motion of the subject to the display unit represented by the subject movement information are in opposite directions and the differences in magnitude are within a threshold value. <EOS>