To provide an evaluation method of a software development manhour cost capable of evaluating the software development manhour cost with an objective and fair technique.

The estimation and evaluation of a development cost of software is carried out by dividing a functional scale (function points) of the software by a productivity coefficient expressed by multiplication of a development language-based productivity value, a productivity adjustment coefficient, a process-based order rate, a work sharing rate and a repair rate, and by multiplying an additional value of the division value thereof and additional work manhours by a system engineer unit cost.