To provide a small sized light weight reciprocating rocking mechanism with a simple structure generating torque rotating a follower even in a position relation in which a driver and the follower are in parallel, and materializing large stroke reciprocating rotation motion.

The reciprocating rocking mechanism is provided with an upward and downward linear motion member 1, a rigid body link 3 pivotally supported at one end, and an elastic body link 2 connecting the linear motion member 1 and the rigid body link 3. Motion of the linear motion member 1 is converted to rocking motion of the rigid body link 3 via the elastic body link 2. The elastic body link 2 moves over a neutral point of deformation during rise and fall of the linear motion member 1 and is deformed to a reverse direction nearly at the neutral point. The elastic link 2 is largely deformed to a top dead center of the linear motion member 1 to accumulate energy, and generates rotary torque rotating the rigid body link 3 downward by that energy at the top dead center. At a bottom dead center of the linear motion member 1, rotary torque rotating the rigid body link upward by energy accumulated by deformation of the elastic body link 2 in a same manner is generated.