Patent ID: 8469881

Claim:
A puncturing apparatus comprising: a housing; a puncturing section that is provided in the housing and punctures skin; a puncturing mechanism that operates the puncturing section; a cylinder having a bottom; a piston having a first end part projecting from the bottom and a second end part that is located in the cylinder and slides along an axis of the cylinder; a first sealing section that seals between the bottom and an outer surface of the piston; a second sealing section that seals between the second end part and an inner surface of the cylinder; a third sealing section that is located in a joint between the piston and the puncturing mechanism and seals between a hollow space opening in the first end part and the puncturing mechanism; and an air chamber that is sealed with the first and second sealing sections and surrounded by the outer surface of the piston and the inner surface of the cylinder, wherein the piston has a connection hole that connects the air chamber with the hollow space.