<p>Disclosed is a lens unit which comprises: first and second lens groups, each of which comprises at least one lens, and which have a focusing function by being arranged in series on the same optical axis; a first lens barrel (1) that holds the first lens group; a second lens barrel (2) that holds the second lens group and contains at least a part of the first lens barrel; and an adjustment mechanism for adjusting the first lens barrel and the second lens barrel with respect to the relative positions of the optical axis directions, the relative inclinations of the optical axes, and the relative eccentricities.</p>
