Provided is a mechanism that causes a rod-shaped member to rotate while causing rod parts, which are part of the rod-shaped member, to carry out out-of-phase reciprocating motions. A drive mechanism (100) in accordance with an aspect of the present invention includes: a rotatable rod (10) that includes rod parts (11) which are separated by a boundary along a central axis 1, the rod parts (11) each being independently movable along the central axis (1); support members (A and B) having a slide groove (31) that is in the form of a ring and that surrounds the rotatable rod (10); and an outer cylinder (50) that is disposed between the rotatable rod (10) and the support members (A and B) and that has longitudinal grooves (51) each extending along the central axis (1).