PURPOSE: To cancel the demerit of making fault analysis difficult caused by being incomplete of fault data in relative modules and the being in existence of massive useless data at the time of fault generation in an information processor provided with plural processors.

CONSTITUTION: An internal bus 4, fault generation report signal line 5 and fault generating module number signal line 6 are connected among respective modules 1, 2 and 3. The respective modules are internally provided with an internal state data preserving means 21, fault detecting means 22, data sample instructing means 23, fault module number informing means 24 and fault data preserving means 25 as shown by the module 2.