A sensor device for tire allowing the sensitivity of a traveling state detection switch to be adjusted, wherein tire inside information is detected in the state of the device installed in a tire air chamber and the detected results are transmitted to the outside. The sensor device for tire comprises a movable member swingable outwardly in a tire radial direction by the centrifugal force of the tire when the tire is rotating and a switch detecting a traveling state in conjunction with the movement of the movable member.