A pressure sensitive sensor is composed of a cylindrical shape body including therein an inner peripheral surface and a hollow portion along a longitudinal direction of that cylindrical shape body, and being made of an elastic electrical insulating member, and a plurality of electrode wires arranged in a helical shape along the inner peripheral surface of the cylindrical shape body, and arranged in such a manner as to have no contact with each other. In the pressure sensitive sensor, in a cross-sectional view perpendicular to the longitudinal direction of the cylindrical shape body, at least some part of the inner peripheral surface of the cylindrical shape body lying between adjacent ones of the plurality of the electrode wires on the inner peripheral surface of the cylindrical shape body is formed in an inner side in radial directions of a circle passing through centers of the plurality of the electrode wires.