A portable information apparatus 20 having communications tools is provided with a switch 22a for instructing enablement/disenablement of transmission functions of the wireless transmission/reception section 21 of the portable information apparatus 20. The portable information apparatus 20, upon receipt of a transmission prohibition signal from an prohibition signal transmitter 31 installed in a public facility 30, determines whether the transmission functions must be disenabled and automatically controls enablement/disenablement of the transmission functions. The portable information apparatus is thus automatically turned off even when the carrier of the apparatus has forgotten to turn off the transmission functions, thereby allowing the carrier to perform necessary operations not involving transmission of electromagnetic waves without causing a nuisance to others.