PURPOSE: An ESL(Electronic Shelf Label) tag is provided to make an antenna touch the upper side or the lower side of a main board, thereby reducing the size of the ESL tag up to the space of the antenna. CONSTITUTION: A main board(220) comprises a communication module(210) which transmits and receives information for a product through a server and wireless communication. A display unit displays product information which is received from the server. A holder antenna includes a protrusion in one end and is connected to the main board through a wire. The holder antenna is an inverse F antenna. One end of a short axis of the inverse F antenna is connected to an antenna connection unit of the main board through a second wire and is operated as an electric supply unit. The other end of a long axis of the inverse F antenna is connected to the antenna connection unit of the main board through a first wire and is operated as the ground. [Reference numerals] (210) Communication module
