To enable a drive recorder to store data at a time when an accident takes place and also to record data after the accident.

Even though vehicle state data are overwritten (S5) while the part from the start address of a flash memory 14 to the end address is skipped except when the vehicle is stopped due to an accident (S4: NO), vehicle state data up to the accident can be stored because the S5 is jumped when travel is stopped due to an accident (S4: YES). When an accident takes place (S6: YES) and the travel is continued (S7: YES), a storage data area is decided, and the start address and the end address of the storage data area are searched (S8). The searched start address and end address are not overwritten because they are skipped by the subsequent S5 processing. Thus, data at an accident can be stored and data after the accident can also be recorded.