To prevent inconvenience due to the misoperation of a portable terminal unit by a visiting care-giver and to prevent medical treatment information from unjustly flowing out even if the portable terminal unit is lost or stolen.

The portable terminal unit (5) obtains information on a person to be cared, which is stored in an identification means (3) that is installed in the house of the person to be cared and can be read by a machine for recognizing an original. Security information is added to obtained information on the person to be cared and it is transmitted to a medical treatment center (6) from the portable terminal unit (5). It is requested that medical treatment information on the person to be cared is transferred to the portable terminal unit (5). Medical treatment information on the person to be cared, which is preserved in the medical treatment center (6), is extracted by setting that information on the person to be cared is included in the transfer request sent to the medical treatment center (6) from the portable terminal unit (5) as a condition, and it is sent to the portable terminal unit (5). Medical treatment information on the person to be cared, which is transmitted from the medical treatment center (6), is received and displayed by the portable terminal unit (5).