ELECTRIC CONDUCTIVITY SENSOR

PROBLEM TO BE SOLVED: To certainly connect a lead wire to electrodes in an electric conductiv ity sensor. SOLUTION: In the electric conductivity sensor 10 equipped with a plurality of electrodes 2, the spacer 5 interposed between the electrodes 2, and a case 7 being a main body housing the electrodes 2 and the spacer 5 and having a flow channel 9 of a liquid or the like formed thereto so as to pierce the electrodes 2, the spacer 5 and the case 7, terminal plates 21 are inserted in the outer peripheries of the electrodes 2 to be fixed thereto and lead wires 4 are respectively soldered to the terminal plates 21 to be able to be certainly connected to the electrodes 2.