To provide a method for managing access to secret data by setting a password according to a secrecy degree of data without reducing convenience of a user as thoroughly as possible.

This data management method has steps: for receiving designation of target data inputted from the user; for receiving the password inputted from the user; and for deciding whether the access to the target data is possible or not, on the basis of information related to an expiration date of the password preset correspondingly to the target data, and a lapsed time to the present from time when the password is lastly updated.