This invention relates to a view angle adjustment mechanism that causes a view element tilting section holding a view element to be supported by a tilting support section via a forcible fitting-type pivot to perform view angle adjustment. A pivot is assembled by forcible fitting between a pivot convex and a pivot concave. The pivot convex includes a spherical surface. The pivot concave includes a surface formed by arranging two conical surfaces so as to face in respective directions opposite to each other along a center axis X of the pivot concave. The spherical surface of the pivot convex is inscribed in the two conical surfaces of the pivot concave.