A puncture device includes a puncture needle having a double structure including an outer needle and an inner tube located in the outer needle； a housing unit accommodating the puncture needle； and a puncture mechanism provided within the housing unit. The puncture mechanism includes a push-in unit configured to be pushed in with respect to the housing unit, an outer needle slide unit attached to the outer needle and configured to slide within the housing unit, a stopper providing releasable fixation between the push-in unit and the outer needle slide unit and releasable fixation between the inner tube inserted into the outer needle and the outer needle slide unit, an elastic member, a first end of which is fixed to the housing unit and a second end of which is fixed to the outer needle slide unit, and a fixation release unit configured to release the fixation between the push-in unit and the outer needle slide unit and the fixation between the outer needle slide unit and the inner tube.
