An air damper consists of a tubular cylinder with opposite ends, a piston movable in the cylinder, a first coil spring for resiliently biasing the piston in the direction of one end of the cylinder, a string for transferring dampening effect produced by a motion of the piston to an openable object, a shaft with a flange slidably fitted into the piston and a second coil spring interposed between the flange of the shaft and the piston inside the first coil spring. The second coil spring exerts a resilient biasing force at later stages of the motion of the piston in the direction of the other end of the tubular cylinder.