A communication device conforming with plural communication standards and having a storage storing a plurality of virtual stacks each having an application program and communication program that implements a protocol stack for communication by the application program. An executor executes the virtual stacks, and a switching controller switches the virtual stacks to be executed by performing a first processing in which at least one part of at least one of the virtual stacks is read from storage and stored into a memory of, and executed by, the executor. Then, in accordance with free capacity in the memory, at least one part of at least one of the virtual stacks executed in the first processing is deleted from memory. In a second processing at least one part of at least one of the virtual stacks is read from the storage and stored into the memory of, and executed by, the executor.