Since the introduction of general anesthesia in 1846, surgical procedures may be carried out while the patient remains insensitive to pain and other external stimuli. As with many other manufactured products, the machines used for anesthesia have changed as technology developed within the industrial and military fields. In this sense, it is easy to understand that modern anesthesia machines include accurate electronic sensors, complex embedded computers, and high‐precision mechanic elements in order to ease the operative procedures to the anesthesiologists and, at the same time, grant the security of the patient. Although anesthesia has been generally described as the part of the medical profession that ensures that the patient remains insensitive to pain and other stimuli during surgical operations, the currently accepted role for the anesthesiologist includes all of the procedures that have to be performed to offer a completely balanced anesthesia. For this purpose, the anesthetic equipment used in many operating rooms includes the machines required for the delivery of vaporized and intravenous agents in order to allow the proper sedation method for each patient and surgical procedure. This chapter will try to provide an operationally centered review of the different elements such as the gas supply system, the gas mixing subsystem, the vaporizer for inhaled agents, the mechanical ventilator, the breathing circuit of the patient, the absorber of CO 2 removal, the infusion pumps required for intravenous anesthesia, and the monitoring subsystem for patient and equipment supervision.