When a trouble occurs in a machine tool (20) sold by a machine tool manufacturer to a customer, a failure analysis apparatus (11) installed in a service center (10) of the machine tool manufacturer remotely controls the machine tool (20) to obtain operation information or alarm information of the machine tool (20) and performs failure analysis based on such information. In the service center (10), a plurality of failure analysis apparatuses (11) comprising personal computers, and a server (12) which are connected to the failure analysis apparatuses (11) for communication and to which a global IP address for the exclusive use is allocated are installed. Machine tools (20) of customers are connectable to the server (12) via the Internet (30).