To provide a small and easy-to-manufacture sealing-up device that allows to easily inject a magnetic fluid and is free from leakage of the magnetic fluid during transportation and installation.

A medium-side outer shield element 5, a bearing-side outer shield element and an inner shield element 7 with one end inserted in the space defined by both outer shield elements form a U-sectioned passage. The inner shield element 7 is provided with a magnet portion 4 molded integrally with its radially outward portion, and is coated with an oil-repellent material 8 on its surface outside the space and except its radially inward glued portion. The medium-side outer shield element 5 has an inside diameter larger than the bearing-side outer shield element.