An ultrasonic joining apparatus comprising: a rotator made of a member to be expanded or contracted by heat; a plurality of anvils provided at predetermined intervals in a rotation direction of the rotator; an ultrasonic horn configured to output ultrasonic vibrations; and a temperature adjustment mechanism configured to adjust a temperature of the rotator, wherein the rotator and the ultrasonic horn are arranged to face each other with an intermediate web being conveyed therebetween, the intermediate web including a continuous first web and a continuous second web overlapping with each other, each of the anvils and the ultrasonic horn pinch a certain region of the intermediate web to perform ultrasonic joining on the certain region, the temperature adjustment mechanism is arranged in each of the anvils, each of the anvils includes: a projection (220, 230) protruding in a normal direction of the rotator; a plurality of protrusions (240, 250) protruding from the projection in the normal direction; characterized in a heat transmitter configured to transmit heat generated by the temperature adjustment mechanism to the rotator and in that the temperature adjustment mechanism and the heat transmitter are arranged between a rotational axis of the rotator and the projection (220, 230), the heat transmitter is arranged in each of the plurality of anvils, and the temperature adjustment mechanism is configured to adjust the temperature on a per anvil basis. a rotator made of a member to be expanded or contracted by heat; a plurality of anvils provided at predetermined intervals in a rotation direction of the rotator; an ultrasonic horn configured to output ultrasonic vibrations; and a temperature adjustment mechanism configured to adjust a temperature of the rotator, wherein the rotator and the ultrasonic horn are arranged to face each other with an intermediate web being conveyed therebetween, the intermediate web including a continuous first web and a continuous second web overlapping with each other, each of the anvils and the ultrasonic horn pinch a certain region of the intermediate web to perform ultrasonic joining on the certain region, the temperature adjustment mechanism is arranged in each of the anvils, each of the anvils includes: a projection (220, 230) protruding in a normal direction of the rotator; a plurality of protrusions (240, 250) protruding from the projection in the normal direction; characterized in a heat transmitter configured to transmit heat generated by the temperature adjustment mechanism to the rotator and in that the temperature adjustment mechanism and the heat transmitter are arranged between a rotational axis of the rotator and the projection (220, 230), the heat transmitter is arranged in each of the plurality of anvils, and the temperature adjustment mechanism is configured to adjust the temperature on a per anvil basis. a projection (220, 230) protruding in a normal direction of the rotator; a plurality of protrusions (240, 250) protruding from the projection in the normal direction; characterized in a heat transmitter configured to transmit heat generated by the temperature adjustment mechanism to the rotator and in that the temperature adjustment mechanism and the heat transmitter are arranged between a rotational axis of the rotator and the projection (220, 230), the heat transmitter is arranged in each of the plurality of anvils, and the temperature adjustment mechanism is configured to adjust the temperature on a per anvil basis.