A manipulation mechanism for moving an oscillating body in a soft endoscope in a stable locus such as for laparoscopic procedures. The mechanism has first and second oscillating portions oscillating on first and second imaginary planes and guide members which regulate oscillating locus of the first and second oscillating portions. A manipulation stick is fixed to the second oscillating portion and capable of moving on the second imaginary plane. The oscillating portions respectively have a force-transmitting-member attachment member, a pair of first support members, and a force receiving member. The pair of first support members is provided with first and second convex portions and each of the first and second guide members is provided with first and second groove portions formed so as to be closer to each other in a direction away from the manipulation reference plane.
