A lens barrel is removeably attachable to an image pickup unit, wherein a large amount of shake can be corrected. This lens barrel includes a mounting part that is removeably attachable to an image pickup unit, including: an image forming optical system that forms a subject image for the image pickup unit; a support unit that supports at least a portion of the image forming optical system; and a fixed unit that is disposed outside of the support unit and that is fixed to the mounting unit. The support part is relatively rotatable and moveable with respect to the fixed unit, about at least two axes which are substantially orthogonal to the light axis of the image forming optical system.