To form a program code for controlling a vehicle by using a program code forming technology using a model by abstracting language.

Variable information for indicating whether or not to be a vehicle characteristic variable characteristic of vehicle control is added to the model in the form of a variable name. A code forming tool 1 acquires the variable information by taking out the variable name to an intermediate file by an extracting engine 10. A code forming block 20 forms a program code characteristic of the vehicle to the vehicle characteristic variable by using a variable forming rule 32 stored in a rule storage part 30. Actually, the program code is formed to be separately treated from an ordinary variable on a memory area for holding the variable, a data type of the variable, and initializing processing to the variable.