A driving mechanism comprises: (i) an actuator comprising: an electro-mechanical conversion element; and a driving member which moves according to elongation and contraction of the electro-mechanical conversion element; (ii) a driven member frictionally engaged with the driving member; and (iii) a case, wherein the actuator allows the driven member to move along the driving member, and the actuator is supported by the case laterally in elongating and contracting directions of the electro-mechanical conversion element.