A device for a machine tool, which is detachable from an attachment part of the machine tool, includes: a data generating unit that generates data; a first communication unit that transmits the data generated by the data generating unit to an information processing device; a first control unit that activates and controls the first communication unit; a power receiving unit that receives power supplied from outside and transmits the power to the first control unit; a second communication unit capable of constantly communicating with the information processing device; a battery that supplies power to the second communication unit; and a second control unit that supplies power from the battery to the first control unit to activate the first control unit when the second communication unit has received an activation command from the information processing device.