A rotary impact tool comprising: a motor ; an impact mechanism including: a hammer configured to rotate by a rotational force of the motor; an anvil configured to rotate by receiving a rotational force of the hammer; and a mounting portion configured to attach a tool bit to the anvil, the impact mechanism being configured such that, in response to application of a torque equal to or greater than a specified value to the anvil, the hammer is detached from the anvil to rotate idle and to then apply an impact to the anvil in a rotational direction of the hammer; an impact detector configured to detect the impact applied to the anvil by the hammer; a controller configured to execute drive control of the motor characterized in that said control includes constant duty ratio control and constant rotation speed control, the controller being configured to execute the constant duty ratio control from the start of the motor until detection of the impact by the impact detector, the controller further being configured to execute the constant rotation speed control in response to detection of the impact by the impact detector, the constant duty ratio control being a control method in which a conduction current to the motor is controlled at a constant duty ratio, and the constant rotation speed control being a control method in which the conduction current is controlled so that a rotational speed of the motor approaches a constant rotational speed. a motor ; an impact mechanism including: a hammer configured to rotate by a rotational force of the motor; an anvil configured to rotate by receiving a rotational force of the hammer; and a mounting portion configured to attach a tool bit to the anvil, the impact mechanism being configured such that, in response to application of a torque equal to or greater than a specified value to the anvil, the hammer is detached from the anvil to rotate idle and to then apply an impact to the anvil in a rotational direction of the hammer; a hammer configured to rotate by a rotational force of the motor; an anvil configured to rotate by receiving a rotational force of the hammer; and a mounting portion configured to attach a tool bit to the anvil, the impact mechanism being configured such that, in response to application of a torque equal to or greater than a specified value to the anvil, the hammer is detached from the anvil to rotate idle and to then apply an impact to the anvil in a rotational direction of the hammer; an impact detector configured to detect the impact applied to the anvil by the hammer; a controller configured to execute drive control of the motor characterized in that said control includes constant duty ratio control and constant rotation speed control, the controller being configured to execute the constant duty ratio control from the start of the motor until detection of the impact by the impact detector, the controller further being configured to execute the constant rotation speed control in response to detection of the impact by the impact detector, the constant duty ratio control being a control method in which a conduction current to the motor is controlled at a constant duty ratio, and the constant rotation speed control being a control method in which the conduction current is controlled so that a rotational speed of the motor approaches a constant rotational speed. <EOS>