A video synthesis device that transforms and synthesizes a plurality of videos input from a plurality of cameras (110-1, 110-2, 110-3, 110-4) and outputs a synthesized video to a video display unit, comprising: - an object-of-interest information acquiring unit that acquires position information related to an object of interest; and - a transforming/synthesizing unit that transforms and synthesizes the plurality of videos photographed by the plurality of cameras (110-1, 110-2, 110-3, 110-4), wherein the transforming/synthesizing unit transforms and synthesizes a virtual projection state in which the videos photographed by the plurality of cameras (110-1, 110-2, 110-3, 110-4) are projected onto a virtual projection plane into a video viewed from a virtual viewpoint set according to position information related to the object of interest, characterized in that the transforming/synthesizing unit sets the virtual viewpoint at a position at which an angle formed by a straight line connecting the virtual viewpoint with the object of interest and a straight line connecting the object of interest with a camera that images the object of interest among the plurality of cameras (110-1, 110-2, 110-3, 110-4) is smaller than a predetermined angle, wherein the predetermined angle is decided so that distortion of a video of the object of interest in the synthesized image is minimized according to a distance between the object of interest and a first crossing point of the straight line connecting the object of interest with the camera that images the object of interest among the plurality of cameras (110-1, 110-2, 110-3, 110-4) and a deviation amount, wherein said deviation amount is a distance from a second crossing point of the virtual projection plane and the line connecting the virtual viewpoint with the object of interest to the first crossing point. - an object-of-interest information acquiring unit that acquires position information related to an object of interest; and - a transforming/synthesizing unit that transforms and synthesizes the plurality of videos photographed by the plurality of cameras (110-1, 110-2, 110-3, 110-4), wherein the transforming/synthesizing unit transforms and synthesizes a virtual projection state in which the videos photographed by the plurality of cameras (110-1, 110-2, 110-3, 110-4) are projected onto a virtual projection plane into a video viewed from a virtual viewpoint set according to position information related to the object of interest, characterized in that the transforming/synthesizing unit sets the virtual viewpoint at a position at which an angle formed by a straight line connecting the virtual viewpoint with the object of interest and a straight line connecting the object of interest with a camera that images the object of interest among the plurality of cameras (110-1, 110-2, 110-3, 110-4) is smaller than a predetermined angle, wherein the predetermined angle is decided so that distortion of a video of the object of interest in the synthesized image is minimized according to a distance between the object of interest and a first crossing point of the straight line connecting the object of interest with the camera that images the object of interest among the plurality of cameras (110-1, 110-2, 110-3, 110-4) and a deviation amount, wherein said deviation amount is a distance from a second crossing point of the virtual projection plane and the line connecting the virtual viewpoint with the object of interest to the first crossing point.