To provide a guide mechanism configured such that if an abnormal state arises in operation during the drive of the guide member, the abnormal state can immediately be detected, and to provide a lens barrel, and a camera.

The guide mechanism includes: a first member (60) having a guide part (61) molded in two colors from a material (68), which can be plated and a material (69) which cannot be plated easily, and having conducting parts (69, 69A, and 69B) formed by metal-plating the surface of a portion formed from the material which can be plated; and a second member (50), moved relative to the first member (60) and having a conductive guided part (51) guided by the guide part (61) during the relative movement. The guide mechanisms (50 and 60) are such n that if a force different from that applied during a normal operation is applied to at least the first member (60) or second member (50) during the relative movement, the state of contact between the conducting parts (69, 69A, and 69B) of the guide part (61) with the guided part (51) is changed.