1. A steam sterilizer (1) for medical instruments, comprising a delivery system (30) suitable for feeding into the sterilization chamber (20) and having at least one main tank (31) for the sterilizing medium (1a), an emptying system ( 40) suitable for discharging the effluent medium (1b) from said sterilization chamber (20), characterized in that it comprises a cleaning system (50) suitable for collecting at least one of the mentioned media (1a, 1b), at least one of the mentioned systems (30, 40) and its supply to the said main tank (31), while said cleaning system (50) comprises a cleaning agent (51) suitable for filtering said medium. The steam sterilizer (1) according to claim 1, wherein said cleaning system (50) comprises a sampling circuit (52) suitable for providing communication between said main tank (31) and said cleaning means (51) to form a passage for medium, and an unloading circuit (53) suitable for providing a message for said cleaning agent (51) and said main tank (31) in order to form a passage for the medium. 3. The steam sterilizer (1) according to claim 1, wherein said cleaning system (50) comprises a secondary intake circuit (54), suitable for communicating said emptying system (40) and said cleaning means (51) to form a passage for the medium. four. The steam sterilizer (1) according to claim 3, wherein said emptying system (40) comprises an unloading tank (41) suitable for containing said outlet medium (1b) and wherein said secondary intake circuit (54) is suitable for providing communication said discharge tank (41) and said cleaning agent (51) to form a passage for the medium. 5. The steam sterilizer (1) according to claim 1, wherein said si1. Паровой стерилизатор (1) для медицинских инструментов, содержащий систему подачи (30), пригодную для подачи в стерилизационную камеру (20) и имеющую, по меньшей мере, один главный бак (31) для стерилизующей среды (1a), систему опорожнения (40), пригодную для сброса выходящей среды (1b) из упомянутой ст
