In a mobile communication device, when an inquiry packet sent from another mobile communication device for inquiring whether to accept or deny the participation in an ad hoc network is transferred to a work area, a transmission/reception control section determines whether or not a denial flag set in a storage device is 1. When the denial flag is 1, the transmission/reception control section generates a first response for denying the participation in the ad hoc network, and transmits the first response through a transmission/reception section to the other mobile communication device that transmitted the inquiry packet.