A powertrain unit (10) includes an engine (20) and a power transmission device that transmits drive force of the engine to a drive wheel, the power transmission device including a transmission (36) provided in a power transmission path between the engine and the drive wheel (39T). An oil pan (35D) is provided below the transmission. A guard member (40) covering at least a portion of the oil pan from below is provided below the oil pan. The guard member (40) has one end secured to a portion of the powertrain unit which is located in front of the transmission (36) in a vehicle longitudinal direction, and has the other end secured to a portion of the powertrain unit which is located behind the transmission (36) in the same direction. The rigidity of the powertrain unit can be improved by utilizing the rigidity of the guard member (40).