A slide operation apparatus capable of preventing a movable unit from being unintentionally moved in a box body, while being easy to assemble and simple in construction. The movable unit includes a gondola to which an operating element is fixed. The gondola is adapted to be movable relative to upper and lower guide bars. A sliding contact assembly includes a plate spring to which an insulation sheet is assembled. The sliding contact assembly in a curved state is mounted to a fixture portion of the operating element by having pawls of the plate spring engaged with notches formed in the fixture portion. During the entire movement process of the movable unit, the curved convex portion of the sliding contact assembly is in sliding contact with the lower guide bar.