1. A device for distributing a load and managing power, comprising: a monitoring unit configured to monitor a load distribution condition on server nodes included in a server cluster and a dynamic state of each of the server nodes; a server node information storage unit configured to store static state information of each of the server nodes; a policy determination unit configured to determine a load distribution policy and a power management policy for each of the server nodes using information monitored by the monitoring unit and the static state information stored in the server node information storage unit; and a controller configured to control conversion of the server nodes into an active state or an inactive state according to the power management policy, and distribution of a load of a service request requested by a service client to activated server nodes according to the load distribution policy; wherein the power management policy determination unit manages an active server node table which sets and manages an order of priority of the server nodes which are activated, and an inactive server node table which sets and manages an order of priority of server nodes which are deactivated; and wherein the power management policy determination unit determines a policy so as to convert the server nodes into the active state in order of having a higher priority in the inactive server node table, and determines a policy so as to convert the server nodes into the inactive state in order of having a lower priority in the active server node table.