A robot includes a joint and a drive mechanism disposed in the joint. A reducer includes an output shaft and a fixed portion. A first seal seals a gap between the output shaft and the fixed portion. A first cover is fixed to the fixed portion and covers an outer surface of the fixed portion. An intermediate portion is fixed to an output-side portion of the output shaft. A second cover is fixed to an output-side portion of the intermediate portion and covers an outer surface and an output-side edge of the first cover. A second seal seals a gap between the first cover and the intermediate portion. A groove extends approximately over a circumference of the outer surface of the first cover.