PURPOSE: To provide a rotary damper minimized with the effect of gravitation.

CONSTITUTION: This rotary damper 10 comprises a housing 12, a cover 16, a rotor 24 provided with vanes 34, a coil spring 54, and an annular seal 40. In a gap space 48, a recess 50, and a small gap 36, viscous fluid such as silicone oil is filled. In using the rotary damper 10 for braking a cover of a glove box in an automobile, for example, a pinion 2 7 is engaged with a rack. In assembling it, the spring 54 is energized in a cover opening direction when the cover is closed. When unlocked, shock of opening of the cover is extremely small.