A piece of mechanized surgical equipment is provided, which includes an instrument holder having an element for receiving and retaining a surgical instrument for mechanized use. Also provided is a surgical instrument for mechanized use and configured to be mounted on the instrument holder. The element for receiving and retaining is mobile between an unlocking position, in which the element enables insertion of the instrument into the instrument holder or withdrawal thereof, and a locking position, in which the element prevents the withdrawal of the instrument from the instrument holder. Furthermore, the equipment includes a case in which an active blade of the instrument can be removably housed, the case having an engaging element for engaging with the receiving and retaining element so as to cause the element to move from the unlocking position to the locking position, or vice versa.