An infrared sensor comprises a base substrate including a recess, a bolometer infrared ray receiver, and a Peltier device. The bolometer infrared ray receiver comprises a resistance variable layer, a bolometer first beam, and a bolometer second beam. The Peltier device comprises a Peltier first beam formed of a p-type semiconductor material and a Peltier second beam formed of an n-type semiconductor material. The Peltier device is in contact with a back surface of the bolometer infrared ray receiver. One end of each of the bolometer first beam, the bolometer second beam, the Peltier first beam, and the Peltier second beam is connected to the base substrate. The bolometer infrared ray receiver and the Peltier device are suspended above the base substrate. Each of the bolometer first beam, the bolometer second beam, the Peltier first beam, and the Peltier second beam has a phononic crystal structure including a plurality of through holes arranged regularly.