An apparatus for transmitting personal information in individually unidentifiable way, includes a communication unit connected with external terminals through a network and performing communication; a controller generating an unidentifiable identifier (ID) of the apparatus and setting a transmission cycle period, at least one acquisition interval and at least one disclosure interval; a list generator acquiring at least one ID list disclosed by an external terminal through the communication unit, and generating an ID list for storage, an ID list acquired in acquisition interval, an ID list for disclosure, and an ID list for transmission; and a memory storing the ID list for storage, the ID list acquired in acquisition interval, the ID list for disclosure, and the ID list for transmission, generated by the list generator.