Disclosed are a message service provision method for providing a message service via an open chat room corresponding to link information, and a message server and a terminal for executing the message service provision method. The message service provision method comprises the steps of: transmitting, to a message server, a request for issuing link information for an open chat room via a message application; receiving, from the message server, link information generated in response to the request for issuing link information; sharing the link information according to a request for sharing inputted by a user of a host terminal; and performing chatting with a user of a guest terminal participating in the open chat room by means of the shared link information; wherein the user of the guest terminal and the user of the host terminal are users who subscribed to a message service provided via the message server.