To provide a lens frame device of an electronic camera, which can secure the improvement of the position detecting accuracy of a moving lens frame.

This lens frame device 1 equipped with the lens frame 15 made movable in an optical axis O direction is equipped with a detection sensor 21 detecting the position of the lens frame in the optical axis direction and a lead screw 22a moving the lens frame, and the lens frame has an interposing part 16c interposing the screw surface of the lead screw, and is provided with rack parts 16bb and 16cc screwed on the screw surface on the inner surface of the interposing part, and a thin part 16b being one part of the interposing part and elastically deformed at the opposed part to the rack part. Furthermore, the lens frame has a torsion spring 24 pressing the rack part to the screw surface, and a detecting armature 16aa for a detection sensor, and the one end of the torsion spring is made to abut on the thin part and the other end thereof is made to abut on the opposed part to the thin part so that the rack part may be pressed to the lead screw, and is provided with the detecting armature at one part of the opposed part to the thin part.