To provide an oil pan correctly regulating the discharge of lubricating oil and the amount of lubricating oil sealed by using one lubricating oil discharge hole.

This oil pan is provided with a cylindrical lubricating oil regulating wall 12 protruding from the bottom surface of the oil pan 1 and formed with a lubricating oil regulating passage 14 formed at an inner periphery and communicating with the outside of the oil pan 1. The lubricating oil regulating wall 12 is formed with the lubricating oil discharge hole 13 at its lower portion. A cylindrical lubricating oil regulating plug 20 closing the lubricating oil discharge hole 13 and formed with a communication hole 23 communicating with the lubricating oil regulating passage 14 is detachably assembled to the lubricating oil regulating passage 14. The communication hole 23 is closed by a detachable drain plug 30.