[Problem] To provide a puncture device and a method for implanting a cannula, whereby a cannula can be reliably implanted in a living body. [Solution] A puncture device has: a main body 10 capable of being affixed to the surface of a living body； a puncture needle provided with a cannula and an inner needle inserted in the cannula； a housing for accommodating the puncture needle； a puncture mechanism for performing a puncture operation for making it possible to withdraw the inner needle from the main body with the cannula still protruding after the puncture needle is caused to protrude from the main body, the puncture mechanism being provided in the housing； and a fixing mechanism 120 for fixing the cannula to the main body in a state in which the puncture needle is caused to protrude from the main body. The puncture mechanism is provided with a puncture needle retaining part including a first retaining part 130 and a second retaining part for retaining the inner needle, and an urging member for imparting to the puncture needle retaining part an urging force in the protrusion direction in which the puncture needle is caused to protrude from the main body. The fixing mechanism is provided with an engaging part 150 for engaging the first retaining part with the main body in conjunction with the operation whereby the first retaining part moves relative to the main body in a direction other than the protrusion direction.[Problème] Fournir un dispositif de ponction et un procédé d'implantation d'une canule, de sorte qu'une canule puisse être implantée de façon fiable dans un corps vivant. [Solution] La présente invention concerne un dispositif de ponction qui comporte : un corps principal 10 pouvant être fixé à la surface d'un corps vivant ； une aiguille de ponction pourvue d'une canule et d'une aiguille interne insérée dans la canule ； un boîtier pour loger l'aiguille de ponction ； un mécanisme de ponction pour effectuer une opération de ponction pour permettre le retra
