1. An emulation apparatus for generating an emulator by combining a plurality of source components each describing a processing operation, the emulation apparatus comprising: an obtaining unit that, for each time period of a plurality of time periods in which an emulator usage environment changes, obtains a count of execution frequency of the processing operation performed by the emulator; a combining unit that, according to the count of execution frequency obtained by the obtaining unit, rearranges and combines the source components to generate a source; and a compiling unit that compiles the source generated by the combining unit.