An offload server includes: an application code analysis section configured to analyze source code of an application; a data transfer designation section configured to, on the basis of a result of the code analysis, designate a data transfer to be collectively performed on, before starting GPU processing and after finishing the GPU processing, of variables that need to be transferred between a CPU and a GPU, those which are not mutually referenced nor mutually updated between CPU processing and the GPU processing and which are only to be returned to the CPU as a result of the GPU processing; a parallel processing designation section configured to identify loop statements in the application, and, for each of the identified loop statements, specify a statement specifying application of parallel processing by the GPU and perform compilation.