Rigidity variable device and endoscope

A rigidity variable device comprising:

• a main body having an elongated shape;
• a plurality of higher rigidity portions made of metal, the plurality of higher rigidity portions being included in the main body and arrayed in a separated manner in a direction along a longitudinal axis of the main body;
• one or more lower rigidity portions included in the main body, the one or more lower rigidity portions comprising a shape memory alloy coil disposed between adjacent ones of the plurality of higher rigidity portions and the shape memory coil including a wire wound around an axis parallel to the longitudinal axis, a rigidity of the shape memory alloy coil increasing when heated;
• and
• a switch configured to switch between energization and non-energization of the shape memory alloy coil;
• wherein the switch is electrically connected to the plurality of higher rigidity portions and is electrically connected to the shape memory alloy coil via the plurality of higher rigidity portions;
• and
• the shape memory alloy coil is heated by the energization.