A control device (10) for a supercharging system for supplying compressed intake air to an engine (2) includes: an engine controller (10A) including an engine-signal input part (10A1) and an engine control part (10B1) configured to control an operational state of the engine; and a turbo controller (10B) including a turbo-signal input part (10B1) and a turbo-control part (10B2) including a turbo-control-command-value computing part (10B2a) configured to compute a turbo control command value corresponding to a target boost pressure of the supercharger (3). The boost-pressure control unit is controlled so that a boost pressure of the supercharger reaches the target boost pressure through output of the turbo control command value computed by the turbo-control-command-value computing part to the boost-pressure control unit.