In an emulation apparatus, a processing operation recording unit records processing operations performed by an emulator executing unit and corresponding execution time. A counting unit reads policies defined in a policy storing unit and counts an execution frequency of each processing operation in each policy. According to the counting result of the counting unit, a source combining unit rearranges source components in an optimal order for each policy and combines the rearranged source components to generate a source. A compiling unit compiles the source generated for each policy and generates an emulator for each policy. An emulator selecting unit finds a policy that includes the current time from among the policies defined in the policy storing unit, reads the emulator generated for the found policy from an emulator storing unit, and instructs the emulator executing unit to execute that emulator.