A needle assembly comprising: a needle comprising a hollow needle tube, a needle tip at a distal end of the hollow needle tube, and a cutting face disposed adjacent to the needle tip; and a needle hub that includes a tip and a base end, wherein the needle hub includes a needle tip side end face from which the needle tip projects, wherein the needle hub holds the needle at the needle tip, wherein a projection needle length extending from the needle tip side end face to the needle tip is within a range of 0.50 mm to 1.25 mm, inclusive, and wherein a needle body length extending from the needle tip side end face to a proximal end of the cutting face in within a range of 0.10 mm to 0.70 mm, inclusive, wherein the needle is configured such that a cutting face length of the cutting face is within a range of 0.30 mm to 0.75 mm, inclusive, characterized in that an outer diameter (φ1) of the needle is within a range of 0.15 mm, inclusive, to a length smaller than 0.20 mm, wherein a wall thickness of the needle tube is within a range of 0.02 mm to 0.05 mm, inclusive, wherein the cutting face includes a first cutting face portion at a proximal side of the cutting face, and a second cutting face portion and a third cutting face portion that form a ridgeline at the needle tip on a boundary between the second cutting face portion and the third cutting face portion, wherein a first cutting face portion cutting angle (θ1) formed by a center axial line of the needle tube and the first cutting face portion is more acute than a ridgeline cutting angle (θ2) formed by the center axial line and the ridgeline, wherein the first cutting face portion cutting angle (θ1) is more acute than each of a second cutting face portion cutting angle (α1) and a third cutting face portion cutting angle (α2) formed by the center axial line and the second cutting face portion and the third cutting face portion, respectively, wherein the first cutting face portion cutting angle (θ1) is within a range of 10° to 35°, inclusive, the ridgeline cutting angle (θ2) is within a range of 15° to 40°, inclusive, and each of the second cutting face portion cutting angle (α1) and the third cutting face portion cutting angle (α2) is within a range of 20° to 55°, inclusive. a needle comprising a hollow needle tube, a needle tip at a distal end of the hollow needle tube, and a cutting face disposed adjacent to the needle tip; and a needle hub that includes a tip and a base end, wherein the needle hub includes a needle tip side end face from which the needle tip projects, wherein the needle hub holds the needle at the needle tip, wherein a projection needle length extending from the needle tip side end face to the needle tip is within a range of 0.50 mm to 1.25 mm, inclusive, and wherein a needle body length extending from the needle tip side end face to a proximal end of the cutting face in within a range of 0.10 mm to 0.70 mm, inclusive, wherein the needle is configured such that a cutting face length of the cutting face is within a range of 0.30 mm to 0.75 mm, inclusive, an outer diameter (φ1) of the needle is within a range of 0.15 mm, inclusive, to a length smaller than 0.20 mm, wherein a wall thickness of the needle tube is within a range of 0.02 mm to 0.05 mm, inclusive, wherein the cutting face includes a first cutting face portion at a proximal side of the cutting face, and a second cutting face portion and a third cutting face portion that form a ridgeline at the needle tip on a boundary between the second cutting face portion and the third cutting face portion, wherein a first cutting face portion cutting angle (θ1) formed by a center axial line of the needle tube and the first cutting face portion is more acute than a ridgeline cutting angle (θ2) formed by the center axial line and the ridgeline, wherein the first cutting face portion cutting angle (θ1) is more acute than each of a second cutting face portion cutting angle (α1) and a third cutting face portion cutting angle (α2) formed by the center axial line and the second cutting face portion and the third cutting face portion, respectively, wherein the first cutting face portion cutting angle (θ1) is within a range of 10° to 35°, inclusive, the ridgeline cutting angle (θ2) is within a range of 15° to 40°, inclusive, and each of the second cutting face portion cutting angle (α1) and the third cutting face portion cutting angle (α2) is within a range of 20° to 55°, inclusive.