A passage unit formed with ink ejection ports, an actuator mounted on the passage unit, and a cover member are provided. Further provided is a side plate member that is in contact with a mounting face of the passage unit on which the actuator is mounted. The side plate member has a side plate and an opposing plate that is connected to the side plate. The side plate extends in the longitudinal direction of the passage unit and along a contour line of the passage unit. The side plate is in crosswise contact with the mounting face. The opposing plate is opposed to the mounting face. The cover member is placed at such a position that the actuator and the side plate member are sandwiched between the cover member and the passage unit. The cover member presses the opposing plate toward the passage unit.