To provide a lens mirror trunk which enables prevention of coming out of a cam follower fixed in a frame member, in the lens mirror trunk having a mirror frame advance/retreat mechanism.

In the lens mirror trunk, a second group frame 22 is fitted by insertion in the inner periphery of a cam frame M11 which is supported rotatably. In the cam frame M11, a cam groove 11g is arranged into which the cam follower 66 is fitted, and a shaft section 66d of the cam follower 66 is fixed into a straight-through hole 22f of the second group frame 22 by a press fitting. In the shaft section 66d of the cam follower to be press fitted into the second group frame, a plurality of edges 66s, 66t are formed. When an external force applies upon the cam follower 66 through the cam groove 11g, then the edges 66s, 66t work to engage into the through-hole 22f and the cam follower is prevented from coming out from the through-hole.