A control device for an automatic transmission that outputs a command signal to an actuator to control the automatic transmission. The control device configured with a main control section that receives a state of the automatic transmission, that determines an abnormality in the automatic transmission on the basis of the input state of the automatic transmission, and that outputs to the actuator a main control section command signal for controlling the automatic transmission so as to establish a predetermined shift speed when it is determined that an abnormality is occurring in the automatic transmission; and a monitoring section that determines an abnormality in the main control section and that outputs to the actuator a monitoring section command signal for causing the automatic transmission to establish a neutral state irrespective of the main control section command signal when it is determined that an abnormality is occurring in the main control section.