A miniature movable device comprises a movable part (a mirror, a movable
rod, support arms, and a movable comb tooth electrode) formed on a
substrate and adapted to be displaced in a direction parallel to the
sheet surface of the substrate, a fixing part formed and fixedly mounted
on the substrate, and hinges, each having its opposite ends connected to
the movable part and the fixing part and assuming two flexural conditions
which are reversed in flexural, the hinges being effective to maintain
the movable part at two positions by a self-holding action when it
assumes either flexural condition. The substrate is formed with wall
surfaces which are disposed oppositely to the opposite surfaces of the
hinges over a movable range of the hinges. Spacings between the hinges
and the wall surfaces disposed on the opposite sides thereof are equal to
each other at every point along the lengthwise direction of the hinges
when the hinges assume one of the two flexural conditions (an initial
condition assumed upon manufacture). This eliminates an inconvenience
that during a drying step which follows a wet etching operation during
the manufacture, a liquid may remain on only one side of the hinges to
cause the hinges to be held attracted to the wall surfaces.