The encoded contents of a piece of delivered information is accompanied by an applicable time data indicating a specific time period for authorizing a particular mode of utilization. When a request for utilizing the contents is issued in an information utilization apparatus, it determines if the current time agrees with the time authorizing the requested utilization by referring to the time data annexed to the encoded contents. If the request is acceptable at the current time, a set of processing steps is carried out for decoding the encoded contents and other necessary operations. Thus, an information access control method can be adapted to have flexibility in setting charges and access requirements for the contents of information that can change the value and the mode of utilization with time.