Control device of compression-ignition engine

A control device of a compression-ignition engine, comprising:

• an engine having a cylinder;
• an exhaust gas recirculation system for introducing exhaust gas into the cylinder;
• and
• a controller for operating the engine by compression-ignition combustion of mixture gas inside the cylinder when an operating state of the engine is within a predetermined compression-ignitable range on a low engine load side,
• wherein when the operating state of the engine is within the compression-ignitable range, the controller sets an EGR ratio higher as the engine load becomes lower, and the controller sets the EGR ratio to a predetermined highest EGR ratio when the engine load is at a specific load that is on the low engine load side within the compression-ignitable range, the EGR ratio being a ratio of the exhaust gas with respect to a total gas amount within the cylinder, and
• wherein when the engine load is lower than the specific load, the controller sets the EGR ratio to be lower than the highest EGR ratio.