DAMPER DEVICE

A damper device that suppresses arc discharge between electrodes generated by bubbles in an electro-rheological fluid, includes an inner tube housed in an outer tube forming an outer shell of a damper device. An electrode tube is arranged between the outer tube and the inner tube. An electro-rheological fluid is sealed in the outer tube. The inner tube and the electrode tube constitute a cathode and an anode, respectively, and apply a voltage to the electro-rheological fluid located between the inner tube and the electrode tube. An insulating layer is provided on a surface of the electrode tube on a side facing the inner tube or on a surface of the inner tube on a side facing the electrode tube. When a maximum voltage applied to the electro-rheological fluid is Vmax (V), a thickness t (m) of the insulating layer is set to satisfy Formula (1).