An informational signal processing apparatus comprising an adjustment device that permits a user to adjust a space resolution adjustment value and a time resolution adjustment value output uninterruptedly. From the adjustment values output to the testing terminal, an acquisition device acquires a final adjustment value through a series of adjustments of these adjustment values and an adjustment value in a process of changes all the way to this final adjustment value and transmits them to an accumulation device. The accumulation device stores a final adjustment value through each series of adjustment and history information related to a process of changes in adjustment value all the way to the final adjustment value. Based on the history information, reliability of the final adjustment value can be decided.