LOG OUTPUT DEVICE

PROBLEM TO BE SOLVED: To make it possible to delete even log information with no description about normal termination from a log buffer if the log information is about processing normally terminated.SOLUTION: A buffer optimization processing unit 102 regularly determines for example whether or not there is, in log information of which recording timing is more late than particular log information recorded in a log buffer 101, log information that has a relation determined on the basis of a structure of a program with the particular log information and in which the particular log information can be regarded as log information about processing normally terminated. When there is such log information, the particular log information is deleted from the log buffer 101.