An electronic device includes a chamber having a chamber wall surface defining a liquid-tight sealed space; an electronic unit housed in a liquid-tight case, the case being disposed in the chamber to define an intermediate space between the case and the chamber wall surface; a biasing unit in the chamber that biases the case toward a predetermined neutral position in the intermediate space; a liquid disposed in the intermediate space; and an iris system formed in the chamber such that when the case moves toward a portion of the chamber wall surface, the iris system cooperates with the case to define a flow path through which the liquid in a portion of the intermediate space between the case and the portion of the chamber wall surface flows to another portion of the intermediate space, a cross-sectional area of the flow path decreasing as the case moves closer to the portion of the chamber wall surface.