A puncture instrument (10; 100) comprising: a case (12; 106); a needle assembly (64; 102) movably disposed in the case (12; 106) and comprising a needle (60; 104) having a sharp needle tip and a hub (62; 130) holding the needle (60; 104); and an abutting member (14; 110) movably disposed in the case (12; 106) for abutment against the skin, the needle assembly (64; 102) being movably held by the abutting member (14; 110), wherein when the abutting member (14; 110) is moved toward the proximal end of the case (12; 106), the needle tip is protruded from an end of the abutting member (14; 110), characterized by needle moving means (66; 108) for moving the needle assembly (64; 102), after the needle tip is protruded from the end of the abutting member (14; 110), toward a proximal end of the case (12; 106) to house the needle tip in the abutting member (14; 110), wherein the case (12; 106) has an engaged portion (30; 116) for engaging the abutting member (14; 110) when the puncture instrument (10; 100) is in an initial state, while the abutting member (14; 110) is moved toward the proximal end of the case (12; 106), the needle assembly (64; 102) moves together with the case (12; 106), and once the abutting member (14; 110) and the engaged portion (30; 116) of the case (12; 106) are released from engagement with each other, the needle assembly (64; 102) is displaced relative to abutting member (14; 110), and the needle assembly (64; 102) is released from a state of being held by the case (12; 106) or the abutting member (14; 110), thereby allowing the needle moving means (66; 108) to move the needle assembly (64; 102) toward the proximal end of the case (12; 106). a case (12; 106); a needle assembly (64; 102) movably disposed in the case (12; 106) and comprising a needle (60; 104) having a sharp needle tip and a hub (62; 130) holding the needle (60; 104); and an abutting member (14; 110) movably disposed in the case (12; 106) for abutment against the skin, the needle assembly (64; 102) being movably held by the abutting member (14; 110), wherein when the abutting member (14; 110) is moved toward the proximal end of the case (12; 106), the needle tip is protruded from an end of the abutting member (14; 110), characterized by needle moving means (66; 108) for moving the needle assembly (64; 102), after the needle tip is protruded from the end of the abutting member (14; 110), toward a proximal end of the case (12; 106) to house the needle tip in the abutting member (14; 110), wherein the case (12; 106) has an engaged portion (30; 116) for engaging the abutting member (14; 110) when the puncture instrument (10; 100) is in an initial state, while the abutting member (14; 110) is moved toward the proximal end of the case (12; 106), the needle assembly (64; 102) moves together with the case (12; 106), and once the abutting member (14; 110) and the engaged portion (30; 116) of the case (12; 106) are released from engagement with each other, the needle assembly (64; 102) is displaced relative to abutting member (14; 110), and the needle assembly (64; 102) is released from a state of being held by the case (12; 106) or the abutting member (14; 110), thereby allowing the needle moving means (66; 108) to move the needle assembly (64; 102) toward the proximal end of the case (12; 106).