To provide a planetary gear type transmission with a plurality of stages to facilitate the operation of backlash regulation and enable the shortening of the time therefor.

In a first backlash regulation process, the energizing force of a tensile coil spring 13 is automatically exerted on an integral inner gear unit 24 and the integral inner gear unit 24 is rotated in an energizing direction, and backlashes B between the integral inner gear unit 24 and a division planetary gear 123B and the division planetary gear 123B and a solar gear 122 are removed. In a second backlash regulating process, the energizing force of a compression coil spring 233 is automatically exerted on a regulation division inner gear 224, the regulation division inner gear 224 is rotated in its energizing direction and backlashes between the regulation division inner gear 224 and a division planetary gear 223B and the division planetary gear 223B and a solar gear 222 are removed.