To hold storage of the radio wave condition in a wireless key and/or a smart key in response to the state of a vehicle, and to notice the stored radio wave condition.

The radio wave condition notice system has a vehicle status determination means for determining the status of the vehicle; a radio wave condition determination means for determining the condition of the radio wave; a radio wave condition storage means for storing the condition of the radio wave with a position of the vehicle and date according to the condition of the radio wave determined by the radio wave condition determination means; and a radio wave condition notice means for noticing the stored condition of the radio wave.