A strain sensor resistor includes: a resistive element (thin-film strain-resistive layer) formed nearly at the center of an upper surface of an insulation substrate to be a base; and front surface electrodes layered and formed on either end part of the resistive element and electrically connected to the resistive element. The entire upper part of the resistive element and a part of the front surface electrodes are covered by a protective film (protective coating). Moreover, back surface electrodes electrically connected to the front surface electrodes are formed on either lower end part of the insulation substrate, and end surface electrodes are formed on either longitudinal end surface of the insulation substrate. The strain sensor resistor has a tip shape solder mountable on a circuit board etc. using the back surface electrodes.