Abstract: A wafer carrier including a case having an opening at one end, slots disposed in the case and receiving wafers, and a wireless communication circuitry disposed on an inner sidewall of the case and configured to detect humidity of a gas contained in the case may be provided. The wireless communication circuitry may be further configured to compare the detected humidity with a threshold humidity predetermined, and transmit a first warning signal to an external host via wireless communication when the detected humidity is greater than the threshold humidity.