A thin client system comprising: (a) a server device adapted to allocate resources to form a virtual machine, and to restrict operation on the virtual machine based on a policy information, the operation being instructed from a client terminal, (b) a client terminal adapted to connect to the virtual machine and to instruct operation on the virtual machine, and (c) a policy management device, wherein (d) the policy management device is adapted to receive terminal information including current position information of the client terminal and a user ID, the user ID being information for identifying a user operating the client terminal, from the client terminal, (e) the current position information of the client terminal being its latitude/longitude information, (f) the policy management device is adapted to extract policy information based on the terminal information, and (g) a virtual machine is formed for the client terminal on the server device, (h) the server device is adapted to receive the user ID and policy information of the client terminal, (i) the server device is adapted to control access from the client terminal via the virtual machine in accordance with the policy information of the client terminal received from the policy management device related to at least one of (i) accessing sites carrying confidential information, (ii) activating a web browser and email software, (iii) limiting the login time of the client terminal, (iv) limiting the client terminal's continuous time use, (v) limiting user authorization. (a) a server device adapted to allocate resources to form a virtual machine, and to restrict operation on the virtual machine based on a policy information, the operation being instructed from a client terminal, to allocate resources to form a virtual machine, and to restrict operation on the virtual machine based on a policy information, the operation being instructed from a client terminal, (b) a client terminal adapted to connect to the virtual machine and to instruct operation on the virtual machine, and (c) a policy management device, wherein (d) the policy management device is adapted to receive terminal information including current position information of the client terminal and a user ID, the user ID being information for identifying a user operating the client terminal, from the client terminal, (e) the current position information of the client terminal being its latitude/longitude information, (f) the policy management device is adapted to extract policy information based on the terminal information, and (g) a virtual machine is formed for the client terminal on the server device, (h) the server device is adapted to receive the user ID and policy information of the client terminal, (i) the server device is adapted to control access from the client terminal via the virtual machine in accordance with the policy information of the client terminal received from the policy management device related to at least one of (i) accessing sites carrying confidential information, (ii) activating a web browser and email software, (iii) limiting the login time of the client terminal, (iv) limiting the client terminal's continuous time use, (v) limiting user authorization.