PURPOSE: To obtain a robust sensor which can be assembled economically with high workability by inserting the end part of a wire into a terminal stopper and soldering in place and securing the strands of the wire while separating by means of a contact preventing member thereby preventing electrical contact between terminals.

CONSTITUTION: A terminal 8 is secured in a housing 1 by means of a resin 9 and a wire 10 of signal line is soldered to the terminal 8 and then a resin molded part 11 is secured to its outer periphery. The terminal 8 is provided with a cut for biting into the end part of the wire and the wire part is soldered while constricted into an elliptical shape. A contact preventing member 12 is provided between the terminals 8 in order to prevent short circuit between two strands of the wire soldered to the terminal 8 when they are removed from fixing. The member 12 is secured together with functional components being secured in the housing 1. When the end part of the wire 10 is secured to the terminal 8, each strand is secured to the terminal not with the shortest length but with several turns around the terminal 8.