A bearing unit is provided which includes a shaft (51) to support rotatably, radial bearing (55) to support the shaft (51) circumferentially, a thrust bearing (66) to support the shaft (51) in the direction of thrusting, and a housing (56) having the radial bearing (55) and thrust bearing (66) disposed therein and in which a viscous fluid (57) is filled. The housing (56) has a sealed structure except for a shaft insertion hole (65) formed therein and through which the shaft 51 is introduced. Between the outer surface of the shaft (51) and the inner surface of the shaft insertion hole (65), there is defined a gap (69) having a sufficient width to prevent the viscous fluid (57) filled in the housing (56) from leaking out of the latter. The housing (56) is formed as a one-piece structure by molding a synthetic resin.