A video display system used in mounting a member on a structure , comprising: a storage unit configured to store information on arrangement of a jig for positioning the member on the structure ; a structure arrangement detection unit configured to detect an arrangement of the structure arranged in a real space; and a control unit configured to perform a display process indicating the arrangement of the jig on the structure arranged in the real space on the basis of the information on the arrangement of the jig stored in the storage unit and a detection result obtained by the structure arrangement detection unit ; characterised in that : the structure extends in a predetermined direction with a main surface with which the member is in contact, and the information on the arrangement of the jig includes information on the arrangement of the jig for restricting a position of the member in the predetermined direction; an angle of inclination of the member with respect to the main surface ; and an angle of rotation of the member with respect to an axis orthogonal to the main surface ; and wherein the jig includes a first jig having a first surface and a second jig having a second surface facing the first surface , and the information on the arrangement of the jig includes information on arrangement of the first and second jigs of which the first surface and the second surface abut the member . a storage unit configured to store information on arrangement of a jig for positioning the member on the structure ; a structure arrangement detection unit configured to detect an arrangement of the structure arranged in a real space; and a control unit configured to perform a display process indicating the arrangement of the jig on the structure arranged in the real space on the basis of the information on the arrangement of the jig stored in the storage unit and a detection result obtained by the structure arrangement detection unit ; characterised in that : the structure extends in a predetermined direction with a main surface with which the member is in contact, and the information on the arrangement of the jig includes information on the arrangement of the jig for restricting a position of the member in the predetermined direction; an angle of inclination of the member with respect to the main surface ; and an angle of rotation of the member with respect to an axis orthogonal to the main surface ; and wherein the jig includes a first jig having a first surface and a second jig having a second surface facing the first surface , and the information on the arrangement of the jig includes information on arrangement of the first and second jigs of which the first surface and the second surface abut the member . the structure extends in a predetermined direction with a main surface with which the member is in contact, and the information on the arrangement of the jig includes information on the arrangement of the jig for restricting a position of the member in the predetermined direction; an angle of inclination of the member with respect to the main surface ; and an angle of rotation of the member with respect to an axis orthogonal to the main surface ; and wherein the jig includes a first jig having a first surface and a second jig having a second surface facing the first surface , and the information on the arrangement of the jig includes information on arrangement of the first and second jigs of which the first surface and the second surface abut the member . <EOS>