A radio data communication apparatus and a radio data communication method are disclosed which prevent, even in a situation wherein a circuit state is bad and unstable, repetition of acquisition of an electric field strength and discrimination of whether or not connection is possible until the circuit state becomes good is prevented thereby to prevent drop of a processing speed of a portable terminal and increase of amounts of power consumption of the portable terminal and a radio unit. A radio portable terminal of the radio data communication apparatus includes a portable terminal section for deciding a notification condition of a circuit state based on information of power supplied to the radio portable terminal and issuing a notification of the notification condition, and a portable radio section for receiving the notification of the notification condition and notifying the portable terminal section of the circuit state when the circuit state satisfies the notification condition received from the portable terminal section. The radio portable terminal is operable to connect a radio circuit based on the circuit state of the notification received from the portable radio section to transmit and receive data to and from a server over a radio communication network, a public network and a wire communication network.