A bearing unit includes: a shaft; a radial bearing configured to support the shaft in a circumferential direction; a thrust bearing configured to support one end of the shaft in a thrust direction; a housing having the radial bearing and the thrust bearing disposed in the inside and having a closed structure except a shaft insertion hole into which the shaft is fitted; a coming out preventing member provided on one end side of the radial bearing at which the thrust bearing is provided configured to prevent the shaft from coming out from the radial bearing; and viscous fluid filled in the housing. The coming out preventing member is made of a resin material having a value of a Young's modulus equal to or higher than 3.4 GPa.