Balancer shaft 5 and 6 rotatably set through bearings 11˜14 and an oil pump 2 driven by power from the balancer shaft 5 and 6 are provided in a balancer housing. Oil discharged from an outlet portion 42 of the oil pump 2 is supplied to a main oil gallery 10 through an outlet passage 48. A bearing filter 55 that filters a part of the oil is provided in the outlet passage 48 that extends from the outlet portion 42. A communication passage 50 that branches off from the outlet passage 48 and communicates with the bearings 11˜14 supplies a part of the oil having been filtered by the bearing filter 55 to the bearings 11˜14. By filtering the oil that is going to be supplied to the bearing portion, decrease in durability of the bearing portion can be suppressed.