To provide a rack device with cooler which can prevent the occurrence of such a situation that the number of revolutions of a fan is increased more than needed or a very long time is spent for lowering the temperature in the device to a required value.

This rack device is loaded with a plurality of kinds of printed wiring boards 6, 7a, 7b, 7c, 8a, 8b, 8c, 9a, 9b, 9c, 10a, and 10b in a rack 1 and cools the wiring boards with a cooler 2. The device is provided with a first temperature sensor 4a which detects the temperature in the device, a second temperature sensor 4b which detects the temperature of the outside air, and board information detecting means 6a and 11b which detect the loaded number and operating states of the wiring boards. The device is also provided with a cooler control means 6a which controls the cooling power of the cooler 2 in accordance with the temperatures in the device and outside air detected by means of the temperature sensors 4a and 4b and the information on the loaded number and operating states of the printed wiring boards detected by means of the detecting means 6a and 11b.