A bearing unit wherein a radial bearing for bearing a shaft in the circumferential direction of the shaft and a metallic housing provided with an attaching section are integrated with each other by molding, a resin molded body formed by the molding is so formed as to sealingly contain the radial bearing therein and is provided on one end side in the axial direction thereof with a shaft passing hole through which to pass the shaft, and the inside of the resin molded body is filled with a viscous fluid, whereby the viscous fluid such as a lubricating oil can be prevented from leaking, and the bearing unit can be attached to an object easily and assuredly.