Abstract: A thermal medium and a laser recording device are provided in which medium parameters can be acquired efficiently. According to one embodiment, the thermal medium includes a photothermal conversion layer, a color development layer, a storage mechanism. The photothermal conversion layer converts an applied laser beam into heat. The color development layer develops a color by the heat converted by the photothermal conversion layer. The storage mechanism stores information related to a medium parameter including a photothermal conversion efficiency of the photothermal conversion layer.