A biopsy needle unit includes a biopsy needle and an elastically deformable safety tube for partially covering the biopsy needle inserted to a lumen extending in a longitudinal direction. A marker is arranged on the biopsy needle at a position protruding from an end portion of the safety tube on an opposite side of a needle tip of the puncture needle when the needle tip portion is accommodated in the lumen. The safety tube has portions in which the lumen is curved at least partially with respect to the longitudinal direction so that the safety tube is elastically deformed due to contact between an inner circumferential face of the lumen and an outer circumferential face of the biopsy needle when the biopsy needle is inserted to the lumen to cause frictional resistance between the inner circumferential face of the lumen and the outer circumferential face of the biopsy needle.
