In a valve timing adjusting device, a support section of a planetary carrier supporting a planetary rotator to enable sun-and-planet motion is located on an inner peripheral side of a first center, which is a tooth contact center between a first gear section of the first rotator and a third gear section of the planetary rotator, and is separate from an inner peripheral side of a second center, which is a tooth contact center between a second gear section of the second rotator and a fourth gear section of the planetary rotator. First moment generated in the planetary rotator by a radial load applied to the third gear section by the first gear section is larger than second moment generated in the planetary rotator by a radial load applied to the fourth gear section by the second gear section.