A program processing device has a non-volatile storage, a volatile storage and a controller. The controller has a detector that detects a bit flip in the program, the variable data, and the constant data in the volatile storage, a constant recovery unit that, when the detector detects an error in the constant data, writes the constant data in the non-volatile storage into the volatile storage, and then continues the execution of the program from a point at which the program was being executed before the detector detected the error, and a restart that, when the detector detects an error in one of the variable data and the program, writes the program, the initial value of the variable data, and the constant data in the non-volatile storage into the volatile storage, and then executes the program written into the volatile storage from a beginning of the program.