1. A three-dimensional observation system comprising: image pickup means for picking up two images of an object of observation which have a parallax with respect to the object of observation; image display means for respectively displaying the two images of the object of observation captured by the image pickup means; and optical means for respectively guiding the two images of the object of observation displayed by the image display means to positions in front of the left and right eyes of a plurality of observers who are squarely facing the object of observation, so that the parallax direction of the image pickup means and the respective parallax directions of the plurality of observers squarely facing the object of observation coincide, thus causing a three-dimensional image to be displayed.