An optical fiber fusion splicer comprising: an apparatus body having a heat fusion portion that fusion-splices optical fibers; a windshield cover that is formed so as to be openable and closable with respect to the apparatus body by one or more cover members and that covers the heat fusion portion in a closed state; clamp mounts or holder mounting portions that are provided on both sides both the heat fusion portion of the apparatus body; a coating clamp that holds a coated portion of the optical fiber between a lower clamp member fixed on the clamp mount and an upper clamp member pivotally attached to the lower clamp member so as to be openable and closable with respect to the lower clamp member, or a fiber holder that holds a coated portion of the optical fiber between a base plate and a lid member pivotally attached to the base plate so as to be openable and closable with respect to the base plate, the fiber holder being detachably placed on the holder mounting portion; finger detectors each of which is provided on a side of each clamp mounts or holder mounting portion opposite a side on which the heat fusion portion is provided and each of which detects fingers; a windshield open and close power source that is configured to open and close the windshield cover; and a driving control device that controls a driving of the windshield open and close power source based on detections of the fiber detectors, wherein when both of the finger detectors detect fingers, the driving control device is configured to control the driving of the windshield open and close power source for closing the windshield cover in a state where the windshield cover is open, and for opening the windshield cover after the connection portion inspection is completed. an apparatus body having a heat fusion portion that fusion-splices optical fibers; a windshield cover that is formed so as to be openable and closable with respect to the apparatus body by one or more cover members and that covers the heat fusion portion in a closed state; clamp mounts or holder mounting portions that are provided on both sides both the heat fusion portion of the apparatus body; a coating clamp that holds a coated portion of the optical fiber between a lower clamp member fixed on the clamp mount and an upper clamp member pivotally attached to the lower clamp member so as to be openable and closable with respect to the lower clamp member, or a fiber holder that holds a coated portion of the optical fiber between a base plate and a lid member pivotally attached to the base plate so as to be openable and closable with respect to the base plate, the fiber holder being detachably placed on the holder mounting portion; finger detectors each of which is provided on a side of each clamp mounts or holder mounting portion opposite a side on which the heat fusion portion is provided and each of which detects fingers; a windshield open and close power source that is configured to open and close the windshield cover; and a driving control device that controls a driving of the windshield open and close power source based on detections of the fiber detectors, wherein when both of the finger detectors detect fingers, the driving control device is configured to control the driving of the windshield open and close power source for closing the windshield cover in a state where the windshield cover is open, and for opening the windshield cover after the connection portion inspection is completed.