A needle tube (3) is applied to a biopsy needle, and has a tubular main body section (31), a distal opening section (32) formed at a distal end (31a) of the main body section (31), and a side hole (36) having an engaged surface (38) directed to an opposite side of an opening end (33) of the distal opening section (32) to lock a portion of biological tissue and formed at a position of a proximal end side of the distal opening section (32) in an inner circumferential surface of the main body section (31) when a force of moving the biological tissue entering from the distal opening section (32) toward the distal opening section (32) is applied.
