It is possible to leave records with which analysis of a cause can be efficiently performed when a trouble occurs in an observation target system and realize reduction in the size of the records at the time of recording. The present invention is proposed as a log recording apparatus. This log recording apparatus is provided with: a cell number storage unit to store a cell number table with cell numbers, each being data for identifying a cell number from a state/event combination; a cell number generation unit acquiring data indicating an event and a state from an observation target system, to determine a cell number corresponding to the event and the state with the use of the cell number table stored in the cell number table storage unit and the data indicating the event and the state; a log data generation unit to generate log data which includes the cell number determined by the cell number generation unit; and a log data recording unit to record the log data generated by the log data generation unit.