A lens barrel is provided that includes an optical system, a housing, a cover member, an electronic part, a flexible substrate. The optical system is configured to form an optical image of a subject. The housing supports the optical system in an interior. The cover member supports the housing in a state of covering an opening of the housing. The electronic part is provided in the interior of the housing. The flexible substrate is electrically connected to the electronic part. The flexible substrate has a connection terminal. The cover member has a through-hole formed in a specific direction. The connection terminal is positioned on inside of the through-hole when viewed in the specific direction.