At least one processor for executing a plurality of programs, a storage area which is capable of storing an information element temporarily, and a storage device which is capable of storing the information element, are provided. A certain level of importance is associated with each of the programs themselves or a performance requirement of each program. When a certain information element is output as a result of execution of a certain program from among the plurality of programs, the certain information element is written into the storage area. Then, a plurality of information elements written in the storage area is output to the storage device side in order of precedence from the information element of the executed program, or the performance requirement thereof, having the highest level of importance.