Copiles a series of instructions by optimizing them for a process executed if a variable has a particular value. An optimization compiler including an update instruction detecting section that detects, in a program to be optimized, an update instruction to update a content of a variable or a content of a storage area specified by a variable, a series of instructions detecting section that detects a series of instructions in the target program, a compile section that compiles the detected series of instructions by optimizing the series of instructions for a process executed if the variable or the storage area has a predetermined particular content, and a generating section that generates a set instruction to set a destination address in the control shift instruction to an address of the series of instructions optimized by the series of instructions compile section.