In a program executing apparatus, a code reading section reads intermediate codes into a storage unit. A data-reference analyzing section determines whether the operands of instructions in the intermediate codes stored in the storage unit require a data reference. Each data reference is analyzed for instructions requiring the data reference. A code rewriting section rewrites the operands of the instructions according to the analysis information obtained by the data-reference analyzing section. An address updating section updates the addresses of address-related instructions. After all intermediate codes are interpreted, a main interpreting and executing section starts interpreting and executing the intermediate codes.