A fusion splicing apparatus fusion-splices end faces 1a and 3a of a pair of optical fibers 1 and 3 to each other. The apparatus includes a mirror shaft 21 provided with a mirror 23 that is arranged between the end faces 1a and 3a of the pair of optical fibers 1 and 3 that are faced toward and spaced away from each other and is movable between a first position to reflect an image of the end face 1a and a second position to reflect an image of the end face 3a, a first camera 25 that takes the image of the end face 1a reflected in the first position, and a second camera 27 that takes the image of the end face 3a reflected in the second position.