A game machine for executing games, which is configured to be coupled via a network to other game machines and servers (15, 17), and to be connected to a plurality of input devices, said game machine comprising: a communication processing block configured to receive user operation signals from the input devices for controlling a game executed by the game machine; an acquisition processing section configured to acquire information addressed to a user at an input device; and a notification processing section configured to give notification of the acquired information addressed to the user; wherein if a plurality of users at different input devices that are connected to the game machine are logged in concurrently, the notification processing section is configured to give notification of user identification information identifying an addressee of the acquired information, along with the acquired information, the acquisition processing section, upon receipt of information indicating the presence of an invitation message from one of the servers, the invitation message being addressed from one of the other game machines to one of the users of the game machine, is configured to acquire, from another one of the servers, said invitation message giving an invitation to a game executed on the other game machine; the notification processing section is configured to give notification of information identifying the game, along with the invitation message; and the game machine further comprises a screen generating unit configured to generate an invitation screen for inviting the user identified by the user identification information to an application session if the user operates an input device while notification of the acquired information addressed to the user is being given, and to generate a screen dedicated to a logged-in user different from the user identified by the user identification information if the different user operates the input device while notification of the acquired information addressed to the other user is being given. a communication processing block configured to receive user operation signals from the input devices for controlling a game executed by the game machine; an acquisition processing section configured to acquire information addressed to a user at an input device; and a notification processing section configured to give notification of the acquired information addressed to the user; wherein if a plurality of users at different input devices that are connected to the game machine are logged in concurrently, the notification processing section is configured to give notification of user identification information identifying an addressee of the acquired information, along with the acquired information, the acquisition processing section, upon receipt of information indicating the presence of an invitation message from one of the servers, the invitation message being addressed from one of the other game machines to one of the users of the game machine, is configured to acquire, from another one of the servers, said invitation message giving an invitation to a game executed on the other game machine; the notification processing section is configured to give notification of information identifying the game, along with the invitation message; and the game machine further comprises a screen generating unit configured to generate an invitation screen for inviting the user identified by the user identification information to an application session if the user operates an input device while notification of the acquired information addressed to the user is being given, and to generate a screen dedicated to a logged-in user different from the user identified by the user identification information if the different user operates the input device while notification of the acquired information addressed to the other user is being given. to generate an invitation screen for inviting the user identified by the user identification information to an application session if the user operates an input device while notification of the acquired information addressed to the user is being given, and to generate a screen dedicated to a logged-in user different from the user identified by the user identification information if the different user operates the input device while notification of the acquired information addressed to the other user is being given.