The present invention relates to a variable turbo supercharger. A hydraulic servo drive device (30) for driving a swing mechanism of the variable supercharger is constructed from a servo piston (31) cThe present invention relates to a variable turbo supercharger. A hydraulic servo drive device (30) for driving a swing mechanism of the variable supercharger is constructed from a servo piston (31) connected to a drive shaft (21) of the swing mechanism and from a pilot spool (36) received in a center hole (34) of the servo piston (31) and slid by pilot pressure. A first hydraulic chamber (47) andonnected to a drive shaft (21) of the swing mechanism and from a pilot spool (36) received in a center hole (34) of the servo piston (31) and slid by pilot pressure. A first hydraulic chamber (47) andsecond hydraulic chamber (48) into and from which pressurized oil flows are arranged in a housing (33). In the servo piston (31) are separately arranged a pressure port (51) into which pressurized oi second hydraulic chamber (48) into and from which pressurized oil flows are arranged in a housing (33). In the servo piston (31) are separately arranged a pressure port (51) into which pressurized oil flows from the outside, a first piston port (53) for interconnecting the center hole (34) and the first hydraulic chamber (47), a second piston port (54) for interconnecting the center hole (34) andl flows from the outside, a first piston port (53) for interconnecting the center hole (34) and the first hydraulic chamber (47), a second piston port (54) for interconnecting the center hole (34) andthe second hydraulic chamber (48), and a return port (52) from which pressurized oil flows. the second hydraulic chamber (48), and a return port (52) from which pressurized oil flows.