A fastening tool configured to fasten a workpiece with a fastener including a bolt and a cylindrical hollow collar that is engageable with the bolt, the bolt having a head part integrally formed with a shaft part having a groove, the workpiece being fastened between the head part and the collar, the fastening tool comprising: a bolt-gripping part (180, 185) configured to grip an end region of the shaft part; an anvil configured to be engaged with the collar; a motor configured to drive and move the bolt-gripping part relative to the anvil in a specified longitudinal-axis direction; and a control part configured to control driving of the motor, wherein: when the bolt-gripping part grips the end region of the shaft part and moves relative to the anvil in a specified first direction of the longitudinal-axis direction, the anvil presses the collar fitted onto the shaft part in a second direction opposite to the first direction of the longitudinal-axis direction and inward in a radial direction of the collar, so that swaging of the fastener is started, the fastening tool is configured to clamp the workpiece between the collar and the head part and to crimp a hollow part of the collar to the groove, whereby swaging of the fastener is completed while the end region remains integrated with the shaft part, the fastening tool being characterized in that the control part is configured to perform swaging of the fastener by driving the bolt-gripping part in the first direction while controlling driving current of the motor to become a specified target current value, and to complete swaging of the fastener by stopping driving of the bolt-gripping part based on rotation speed of the motor. a bolt-gripping part (180, 185) configured to grip an end region of the shaft part; an anvil configured to be engaged with the collar; a motor configured to drive and move the bolt-gripping part relative to the anvil in a specified longitudinal-axis direction; and a control part configured to control driving of the motor, wherein: when the bolt-gripping part grips the end region of the shaft part and moves relative to the anvil in a specified first direction of the longitudinal-axis direction, the anvil presses the collar fitted onto the shaft part in a second direction opposite to the first direction of the longitudinal-axis direction and inward in a radial direction of the collar, so that swaging of the fastener is started, the fastening tool is configured to clamp the workpiece between the collar and the head part and to crimp a hollow part of the collar to the groove, whereby swaging of the fastener is completed while the end region remains integrated with the shaft part, when the bolt-gripping part grips the end region of the shaft part and moves relative to the anvil in a specified first direction of the longitudinal-axis direction, the anvil presses the collar fitted onto the shaft part in a second direction opposite to the first direction of the longitudinal-axis direction and inward in a radial direction of the collar, so that swaging of the fastener is started, the fastening tool is configured to clamp the workpiece between the collar and the head part and to crimp a hollow part of the collar to the groove, whereby swaging of the fastener is completed while the end region remains integrated with the shaft part, the fastening tool being characterized in that the control part is configured to perform swaging of the fastener by driving the bolt-gripping part in the first direction while controlling driving current of the motor to become a specified target current value, and to complete swaging of the fastener by stopping driving of the bolt-gripping part based on rotation speed of the motor.