A receiver of a tire status monitoring apparatus which can specify tire mounting positions and does not require initial registration work. The tire status monitoring apparatus includes a plurality of transmitters which are provided on the respective tires of a vehicle and transmit data indicating statuses of the respective tires. The data includes an identification code to identify each tire, and the receiver is supplied with an activation signal to activate a drive source of the vehicle. The receiver includes a reception unit which receives the data from the transmitters, and a control circuit which is connected to the reception unit and collates the identification code included in the data upon detection of the activation signal and specifies, based on the identification code, each transmitter which has transmitted the data.