A lens apparatus of the present invention includes a cam ring 7 having an inner circumferential surface on which first, second, and third cam groove portions 7a, 7b, and 7c with which first, second, and third cam followers 25, 26, and 6 provided on first, second, and third lens holding members 1, 2, and 3 engage. The cam ring introduces the first and second cam followers from an insertion opening 7d and includes an introducing groove portion 7b4 for introducing the third cam follower and a connecting groove portion 7a5. The third cam groove portion is divided at a middle of the introducing groove portion which connects the insertion opening with the second cam groove portion.