PURPOSE: To obtain a two-way touch sensor which has a positively operating detector and has a small size and high accuracy by magnifying the displacement of a measuring element, transmitting the same to the oscillating end side of levers and actuating the detector at the oscillating end.

CONSTITUTION: When a touch sensor is lowered to bring a measuring element 21 into contact with a measuring surface, a probe shaft 19 oscillates counterclockwise around a fulcrum shaft 15, and a lever 29 positioned on the upper side of a contactor 23 oscillates to a turning body 35 side and contacts with the body 35. Then a switch 41 closes to light a display element 51, at the same time, a contact signal is transmitted through a plug 52 to the control section of a measuring machine. The displacement of the element 21 is magnified in two stages by the shaft 19 and a pair of the levers 29 and the switch 41 is operated to open or close by the magnified displacement; therefore, the accuracy in the measurement is improved without increasing the size over the entire part of the touch sensor.