The invention provides an in-wheel motor drive device, which is a connecting structure with excellent operation efficiency in the operation of connecting a bracket on the side of a suspension device with a shell of the in-wheel motor drive device by using a plurality of bolts. The in-wheel motor drive device comprises: a wheel hub bearing unit; a motor unit; a casing for housing the rotation transmission path from the motor rotating shaft of the motor unit to a rotating wheel of the wheel hub bearing unit; a bracket unit (17m) linkable with a suspension device; and an anchoring means for attaching/anchoring the bracket unit to a casing (29). The anchoring means includes: multiple bracket through-holes (17h, 17h) formed in the bracket unit (17m); multiple casing through-holes (46, 46) whichare formed in the casing (29) and connected with the corresponding multiple bracket through-holes; bolts (47) each passing through each of the interconnected bracket through-holes (17h) and the casing through-holes (46); and a female screw member (48) including at least two female screws (48f) into which each of the multiple bolts is screwed.