A fastener driving tool has a housing, a nose portion, a magazine, a motor, a plunger, a drive mechanism, a trigger switch, a detection switch, an energizing switch, a failure detection circuit. The magazine is configured to store and supply a fastener to the nose portion. The motor is provided in the housing. The a plunger is provided in the housing to move between a top dead center and a bottom dead center. The plunger has a blade for impacting the fastener. The drive mechanism is configured to drive the plunger with power from the motor. The trigger switch is configured to drive the drive mechanism, and operated by a user. The detection switch is configured to be switched according to an arrangement of the drive mechanism. The energizing switch is configured to control power feed of the motor. The energizing switch is switched by the trigger switch and the detection switch. The failure detection circuit is configured to turn off the energizing switch, based on a condition of the detection switch prior to impacting the fastener.