A hydraulic pressure amplifier with a housing which has an end face at a low pressure side and an end face at a high pressure side and a circumferential wall between the two end faces, wherein an outlet valve is arranged adjacent the end face on the high pressure side, and an outlet duct for the hydraulic liquid which is under high pressure. In a pressure amplifier of the above-described type, the outlet duct opens into the circumferential wall or extends through a connection plug which is screwed into the end face on the high pressure side and closes off an assembly duct which receives the outlet valve.