<p>A hermetically sealed rush adjuster (100A) comprises a plunger (2A), a body (1) into which the plunger (2A) is inserted, a first seal member (5) provided between the plunger (2A) and the body (1), and a second seal member (20A) arranged to seal a part of the plunger (2A) exposed from the body (1) slidably and to cover a gap (K) formed between the opening end of the body (1) and the plunger (2A) under a state adhering directly or indirectly to the body (1) wherein a hole (1a) for interconnecting the inside and the outside of the wall face of the body (1) is formed at a part of the body (1) closer to the opening end side than the first seal member (5).</p>
