A vehicle is mounted with a pulse detecting unit that detects rotation of a wheel as pulses, a wheel rotation number storage unit that stores the number of pulses detected by the pulse detecting unit in correspondence with time, and a wheel position specifying device that specifies on which of the plurality of wheels the tire state detecting device arranged on each wheel is arranged. The wheel position specifying device includes a reception unit that receives a transmission signal, including a time required for the wheel to make a predetermined number of rotations, transmitted from each tire state detecting device, and a specifying unit that specifies the wheel on which each tire state detecting device is arranged from a difference of the number of pulses counted during the time included in the transmission signal and the number of pulses detected by the pulse detecting unit while the wheel makes the predetermined number of rotations.