A detached-type temperature indicator and method for using the same is disclosed. The indicator includes a temperature sensing module and a temperature display module. These two modules are separated apart with a distance, and the temperature change sensed by the temperature sensing module can be displayed on the separate temperature display module without using any power sources. This indicator is suitable for observing the magnetic sensing patterns which reflect the temperature variations within the package from the exterior of the package without opening the package. Also, this indicator may be used repeatedly.