The invention introduces an apparatus for handling flash physical-resource sets, at least including a random access memory (RAM), a processing unit and an address conversion circuit. The RAM includes multiple segments of temporary space and each segment thereof stores variables associated with a specific flash physical-resource set. The processing unit accesses user data of a flash physical-resource set when executing program code of a Flash Translation Layer (FTL). The address conversion circuit receives a memory address issued from the FTL, converts the memory address into a relative address of one segment of temporary space associated with the flash physical-resource set and outputs the relative address to the RAM for accessing a variable of the associated segment of temporary space.