An optical fiber cutter comprising: a base that includes a pair of clamps (11, 12) disposed with an interval therebetween in a longitudinal direction of an optical fiber; a blade member moving base that includes a disk-shaped blade member and is configured to move the blade member between the pair of clamps and bring an outer circumferential edge of the blade member into contact with a surface of the optical fiber to scratch the surface of the optical fiber; and a pressing member that press-bends a scratched portion of the optical fiber to cut the optical fiber, wherein the blade member is rotatably fixed to the blade member moving base to change a position of the outer circumferential edge to be in contact with the optical fiber, the base further includes a rotating member that is rotatably fixed to the base, the rotating member being configured to transmit power to the blade member by rotation of the rotating member and thereby rotate the blade member, wherein the rotating member is rotated by an electromagnetic force, and power transmission between the blade member and the rotating member is releasable; characterized in that: the blade member includes a fixing member; the rotating member includes an engaging portion configured to engage with the fixing member and a non-engaging portion configured not to engage with the fixing member; the engaging portion and the non-engaging portion are arranged in a rotational direction of the rotating member, and according to a rotational position of the rotating member, the rotating member is configured to be switchable between an engaged state in which the fixing member and the rotating member are engaged and a disengaged state in which the fixing member and the rotating member are disengaged. a base that includes a pair of clamps (11, 12) disposed with an interval therebetween in a longitudinal direction of an optical fiber; a blade member moving base that includes a disk-shaped blade member and is configured to move the blade member between the pair of clamps and bring an outer circumferential edge of the blade member into contact with a surface of the optical fiber to scratch the surface of the optical fiber; and a pressing member that press-bends a scratched portion of the optical fiber to cut the optical fiber, wherein the blade member is rotatably fixed to the blade member moving base to change a position of the outer circumferential edge to be in contact with the optical fiber, the base further includes a rotating member that is rotatably fixed to the base, the rotating member being configured to transmit power to the blade member by rotation of the rotating member and thereby rotate the blade member, wherein the rotating member is rotated by an electromagnetic force, and power transmission between the blade member and the rotating member is releasable; characterized in that: the blade member includes a fixing member; the rotating member includes an engaging portion configured to engage with the fixing member and a non-engaging portion configured not to engage with the fixing member; the engaging portion and the non-engaging portion are arranged in a rotational direction of the rotating member, and according to a rotational position of the rotating member, the rotating member is configured to be switchable between an engaged state in which the fixing member and the rotating member are engaged and a disengaged state in which the fixing member and the rotating member are disengaged. the blade member includes a fixing member; the rotating member includes an engaging portion configured to engage with the fixing member and a non-engaging portion configured not to engage with the fixing member; the engaging portion and the non-engaging portion are arranged in a rotational direction of the rotating member, and according to a rotational position of the rotating member, the rotating member is configured to be switchable between an engaged state in which the fixing member and the rotating member are engaged and a disengaged state in which the fixing member and the rotating member are disengaged.