In a control device for an automatic transmission having a flow control mechanism that causes a part of a working oil discharged from a mechanical oil pump to flow into the mechanical oil pump when a differential pressure between an upstream side and a downstream side of a narrowed portion increases beyond a predetermined value, the narrowed portion being provided in a discharge passage through which the working oil discharged from the mechanical oil pump flows, a line pressure is raised when an oil temperature of the working oil is equal to or higher than a predetermined oil temperature and an engine torque is equal to or smaller than a predetermined engine torque.