To retrieve and display the information registered based on the current position information by adding the current position automatically when registering information.

When new data inputting, data correction, and data reference are done in a portable information terminal unit 1, a current position at the time is acquired by a current position acquiring part 2, and the acquired current position is added to the data in a current position adding part 11 and is stored in a data storage part 3. When the portable information terminal unit 1 is carried to an arbitrary place, a current position at the time is acquired in the current position acquiring part 2, the acquired current position and the current position added to each data stored in the data storage part 3 are checked to retrieve whether there is the current position with which they coincide by a current position retrieval part 12, and the data with which the current positions coincide is sampled in a current position coincidence data sampling part 14. The sampled data is displayed for a user by a list so as to confirm the information used at the same place in the past.