To enable the improvement of comfortableness by preventing a damper stroke from changing, even in case of making a height adjustment.

A device has the first stroke control oil chamber A provided in a side of a rod side oil chamber R1 to change a capacity in accordance with protruding/sinking action of a piston rod 4 and a guide cylinder 12 mounted in a spring guide 21 supporting an upper end of a suspension spring 22 to slidably support the piston rod 4. An upper bracket 11 slidable relating to the guide cylinder 12 is provided in an end of the piston rod 4. Between the upper bracket 11 and the guide cylinder 12, the second stroke control oil chamber B communicating with an oil path 16 through a height setting opening/closing valve 15 is partitioned, also a pressure receiving area of the first/second stroke control oil chambers is almost equally formed.