A server system is provided in which it is possible to avoid an improper operation or malicious operation on, for example, a power switch of a server. In such a system, both a management server and multiple servers are connected to a network. Each multiple server includes: an authentication key storing portion which stores an authentication key; and a management module which compares between data inputted by operating the operation switches and the authentication key stored in the authentication key storing portion, wherein the management module sets the operation switches available if the input data and the authentication key are the same. The management module includes a function of writing the authentication key received from the management server into the authentication key storing portion. The management server includes a virtualized environment software which transmits the authentication key to each of the multiple servers via the network.