Fusion splicer

A fusion splicer comprising:

• an optical fiber holder holding an optical fiber;
• a rotation mechanism rotating the optical fiber holder around an axis extending along the optical fiber;
• a bending portion bending the optical fiber;
• a light source allowing light from the side of the optical fiber to be incident on the optical fiber bent by the bending portion;
• and
• a power supply unit supplying power to the light source,
• wherein a tip of the optical fiber protrudes from an end of the optical fiber holder,
• wherein the rotation mechanism is disposed on the opposite side of the end of the optical fiber holder in the axial direction extending along the optical fiber,
• wherein the bending portion and the light source are disposed on the opposite side of the optical fiber holder interposing the rotation mechanism in the axial direction, and
• wherein the bending portion includes a bending adjustment unit adjusting a bending amount of the optical fiber.