To provide a mechanism capable of precisely fixing a detection element without using any dedicated part for pressing the detection element in an optical axis direction thereby reducing the cost for a lens barrel.

The lens barrel comprises: a diaphragm mechanism 6l that adjusts the diaphragm diameter; a shutter mechanism that opens/closes the imaging optical path; and an image stabilizing mechanism including a detection element 7i that detects an image stabilizing lens and the position of the lens. A holding member 6f for holding the diaphragm mechanism 6l is disposed at the image stabilizing mechanism side, and the holding member 6f is provided with an elastic portion 6c for giving force to the detection element 7i in an optical axis direction.