An instruction conversion apparatus and method for converting instruction sequences not including conditional instructions into instruction sequences including conditional instructions wherein the conditional instructions include both a condition and an operation code for execution by the processor when the condition is satisfied. An obtaining unit receives an instruction sequence that does not include a conditional instruction whereby an instruction sequence detection unit detects a conversion target instruction sequence which transfers different transfer objects to the same storage resource when a predetermined condition is satisfied. A judging unit judges whether the instruction set of a specialized processor is assigned a conditional instruction including the same condition as the precondition whereby a conversion unit can then convert the conversion target instruction sequence into the instruction sequence including a conditional instruction with the predetermined condition. While the judgment unit decision is negative, the conversion unit converts the conversion target instruction sequence into an instruction sequence including a conditional instruction with a condition that is mutually exclusive with the predetemiined condition.