A lens barrel is disclosed that includes a rotational barrel driven to rotate about an optical axis of the lens barrel. The rotational barrel has a plurality of guide grooves formed on an inner periphery thereof. The lens barrel further includes a linear moving barrel guided along the optical axis without rotating about the optical axis, a unit secured inside the linear moving barrel, and a plurality of follower pins securing the unit to the linear moving barrel. The plurality of follower pins each project outwardly from an outer periphery of the linear moving barrel to engage with the plurality of guide grooves, respectively, so that the linear moving barrel is moved along the optical axis relative to the rotational barrel when the rotational barrel is driven to rotate.