To solve the problems wherein it is possible to check time sequential display changes of display data, only with respect to a specific layer, in map data having a multilevel layer structure.

In a display method, a computer copies the data management table of each layer according to the instruction of a user and, while changing display attribute of the data as needed, makes the display data on a specific layer time sequentially change only in a designated period of time. At this time, display data on other layers are kept fixed. For the display data, either of successively displaying the display data in a specific time, or cumulatively displaying the data within the designated period of time is made possible, according to the setting by the user.