To provide a tire pressure regulating valve for regulating pressure in a tire depending on the conditions of road surfaces during the travel of an automobile.

The tire pressure regulating valve 1 comprises a joint 2 and a valve body 3. The joint 2 consists of a joint housing 20 and a thrust member 25. The valve body 3 consists of a valve housing 30, a plunger 33 and a coil spring 36. The valve 1 is mounted on a tire valve 120. When pressure in the tire 100 does not exceed a reference value, a valve portion 34 closes an end opening 31 of the valve housing 30 with the energizing force of the coil spring 36. When the pressure in the tire 100 exceeds the reference value, the pressure in the tire 100 overcomes the energizing force of the coil spring 36 and the valve portion 34 opens the end opening 31.