In a control apparatus for an automobile with a microcomputer, the control software stores the type of the terminal pin allocated to each control function in the fixed storage section, in a non-fixed state by using a terminal pin variable, in order to alter an allocation arrangement of the terminal pin to the control function. A rearrangement table showing the allocation arrangement of the terminal pin to the control function is stored in a rearrangement table storage section. An allocation content of the terminal pin to each control function is read out from the rearrangement table memory section and specific information of a corresponding terminal pin is substituted into the terminal pin variable corresponding to the each control function included in the control software, based upon the allocation content.