An optical fiber cutter comprising: a device main body that includes a lid rotatably mounted with respect to a base; a lower gripping member configured as an integrated member including two lower grippers the two lower grippers being provided on the base and respectively at two positions in a longitudinal direction of an optical fiber; an upper gripping member configured as an integrated member including two upper grippers, the upper grippers being provided on the lid and respectively at two positions in the longitudinal direction of the optical fiber; a gripping mechanism that comprises the two lower grippers provided on the base and the two upper grippers provided on the lid, wherein the gripping mechanism being configured to grip the optical fiber between the lower gripping member and the upper gripping member; a movable blade member configured to scratch a surface of the optical fiber gripped between the lower gripping member and the upper gripping member, the blade member being disposed between the two lower grippers; and a pressing portion configured to press the optical fiber scratched by the blade member to cut the optical fiber, the pressing portion being provided on the lid; wherein: the lower gripping member is separate from the base, the two upper grippers and the two lower grippers are configured to be rotatable about a common rotation fulcrum on the same center line, the base includes a displacement mechanism configured to vertically displace a distal end of the lower gripping member opposite to the base end (43, 53, 63) of the lower gripping member; characterized in that the displacement mechanism includes a vertical member that is vertically movable and a manipulating knob configured to manipulate the vertical member. a device main body that includes a lid rotatably mounted with respect to a base; a lower gripping member configured as an integrated member including two lower grippers the two lower grippers being provided on the base and respectively at two positions in a longitudinal direction of an optical fiber; an upper gripping member configured as an integrated member including two upper grippers, the upper grippers being provided on the lid and respectively at two positions in the longitudinal direction of the optical fiber; a gripping mechanism that comprises the two lower grippers provided on the base and the two upper grippers provided on the lid, wherein the gripping mechanism being configured to grip the optical fiber between the lower gripping member and the upper gripping member; a movable blade member configured to scratch a surface of the optical fiber gripped between the lower gripping member and the upper gripping member, the blade member being disposed between the two lower grippers; and a pressing portion configured to press the optical fiber scratched by the blade member to cut the optical fiber, the pressing portion being provided on the lid; wherein: the lower gripping member is separate from the base, the two upper grippers and the two lower grippers are configured to be rotatable about a common rotation fulcrum on the same center line, the base includes a displacement mechanism configured to vertically displace a distal end of the lower gripping member opposite to the base end (43, 53, 63) of the lower gripping member; characterized in that the displacement mechanism includes a vertical member that is vertically movable and a manipulating knob configured to manipulate the vertical member. the lower gripping member is separate from the base, the two upper grippers and the two lower grippers are configured to be rotatable about a common rotation fulcrum on the same center line, the base includes a displacement mechanism configured to vertically displace a distal end of the lower gripping member opposite to the base end (43, 53, 63) of the lower gripping member; characterized in that the displacement mechanism includes a vertical member that is vertically movable and a manipulating knob configured to manipulate the vertical member.