An image geometric correction device 6 unifies the coordinate systems of images captured by image capturing devices 4-1 and 4-2 into a coordinate system, and makes a geometric correction to the images projected by image projection devices 1-1, 1-2, and 1-3 on the basis of an image projection region E in the coordinate system into which the coordinate systems of the captured images are unified. As a result, the image geometric correction device can make a geometric correction to the projected images without strictly placing the image capturing devices 4-1 and 4-2 at predetermined positions.