A front fork in which a stroke amount of a spring leg that relies on an air spring can be detected precisely, wherein pressure leaks in the spring leg are detectable. The front fork has: a guide cylinder that extends from one of a vehicle body-side tube or an axle-side tube that make up a spring leg; a piston mounted to the leading end of a guide rod extending from the other one of the tubes; an inner airspring chamber in the interior of the guide cylinder; an outer airspring chamber, outward of the inner airspring chamber, in the interior of the vehicle body-side tube and the axle-side tube; first and second detectors for detecting pressure and temperature in the outer airspring chamber the inner airspring chamber, respectively; and stroke detection compensator for detecting a stroke amount on the basis of outputs of the first and second detectors.