PURPOSE: To restrain the state where damping force is extremely increased when damping force is adjusted so as to be decreased, so as to improve riding comfort by forming an intermediate orifice on a rotary valve independent of a damping force adjusting orifice.

CONSTITUTION: An intermediate orifice 18 is formed between a small-diameter orifice 15 and a large-diameter orifice 16 for adjusting damping force on a rotary valve 14, and a communication hole 19 is formed so as to be faced to the intermediate orifice 18. And a rotary valve 14 for shifting the medium state where the orifice 15 is faced to the communication hole 17 to the soft state where the orifice 16 is faced to the communication hole 17 is rotated. At this time, on the way the intermediate orifice 18 is faced to the communication hole 19, thereby a bypass passage is opened. Thereby the damping force is not increased to the hard state. Thus, the damping force is shifted to the soft state without being extremely increased even if it is increased a little when the medium state is shifted to the soft state.