To provide a safety interlock system which can reduce risk in which a load supported may fall when a component of mechanical manipulator conveying load by lifting is broken.

The safety interlock system includes a rotary lever arranged to be operationally connected with a lifter and load support of the mechanical manipulator. Furthermore, this rotary lever is biased in a first rotating direction, and is made to be rotated in an opposite rotating direction by responding to a lifting force applied by the lifter. Additionally, the safety interlock system includes a locking component arranged to engage with a supporting frame of the mechanical manipulator based on a rotation location of the rotary lever, when the component of the manipulator is broken.