The invention provides a lens barrel, an imaging device and an information terminal device using the lens barrel. The lens barrel includes: at least one lens group which constitutes an imaging optical system; a lens frame which retains the at least one lens group; and a retaining frame which retains the lens frame, the at least one lens group being capable of moving from a collapse position to a photographable position, at least one cam member being arranged between the lens frame and the retaining frame, and tilt of the lens frame relative to the retaining frame being changed by moving the at least one cam member.