The present invention relates to a puncture needle (11) formed with a first blade surface (12A), a second blade surface (12B), and a third blade surface (12C). The first blade surface (12A) has a site most distant from a needlepoint formed within a range of 1.5 and 2.5 mm as a distance (D1) in an axial direction (L1) from the needlepoint, and the second and third blade surfaces (12B, 12C) have a site most distant from the needlepoint formed in a range of 0.4 to 0.68 mm as a distance (D2) in the axial direction (L1) from the needlepoint. A ratio (D2/D1) of the distance (D2) with respect to the distance (D1) is preferably set in a range of 0.22 to 0.38.
