To provide a tire valve equipped with a tire air pressure sensing means and a tire air pressure sensing device using the tire valve capable of eliminating damage of a tire when it is mounted and removed and sensing the air pressure properly at all times.

The tire valve 1 is formed in a coaxial structure where an outer skin 5 of resin is molded at the periphery of a valve stem 4 in tubular shape and is fixed to a rim 55 in penetrating it, wherein a coil antenna 3 is embedded in an outer side part 7 of the resin skin 5 protruding to the side of the rim in such a way as winding round the valve stem 4, while a sensor device 2 is embedded in the inner side part 6 of the resin skin 5 protruding to the tire inside from the rim 55. Therefore, the tire valve 1 is in the coaxial structure in the same manner as in any conventional valve arrangement, and is attached to a valve hole 58 formed in the rim 55 easily by a usual fixing means. Also it is easy to make weight adjustment.