Sensor for measuring external input, and pressure-sensitive sensor

A pressure-sensitive sensor is provided with an external force calculation means which holds normalized information (S (FX) ) relating to "external force-resistance characteristic" that is normalized on the basis of a predetermined numerical expression using a resistance value (R (Fmax) ) when the set maximum external force (F max ) of a pressure-sensitive ink member is added, a resistance value (R (F0) ) when no external force is added, and a resistance value (R (FX) ) when external force (F X ) less than the set maximum external force (F max ) is added, the resistance values being measured by a resistance measuring means, and calculates added external force from a resistance value measured by the resistance measuring means on the basis of the normalized information (S (FX) ) relating to "external force-resistance characteristic". Consequently, apparent variations in "external force-resistance characteristic" among pressure-sensitive sensor products can be reduced.