A method or procedure for making something; can mean a recipe in cooking or a manufacturing/formula in industry.
伝統的な製法で作られたチーズは風味が豊かだ。
Cheese made by traditional methods has a rich flavor.
この薬の製法は企業秘密だ。
The manufacturing formula for this medicine is a company secret.
新しい製法を導入して生産効率を上げた。
They introduced a new production method and increased efficiency.