PURPOSE: To automate the packaging operation of a rice ball wrapped with a laver sheet and to enable the mass-production of rice balls, by protruding a part of a tacky adhesive piece from an end of a flat rectangular bag of a thin plastic film, covering both ends of a rice ball having short cylindrical form in cylindrical manner and pasting the protruded part of the tacky adhesive piece to the outer surface of the coating layer.

CONSTITUTION: A rice ball 6 of a short cylindrical form having a length nearly equal to the width of a flat rectangular bag of a thin plastic film 1 is placed on the inner side of the flat bag 1 between covering flaps 3, 3 of both sides and both ends of the rice ball 6 are covered with the covering flaps 3, 3. The covered part (rice ball) is rolled up toward a tacky adhesive piece 5 to effect the covering (7) of both ends and of the rice ball 6 with the covering flaps 3, 3 and the flat bag 1 in cylindrical manner. Continuing to the final stage of the covering process, the protruded part 5' of the tacky adhesive piece 5 is pasted to the outer surface of the cylindrical cover ing 7 to form a cylindrical package resistant to unrolling. Since the tacky adhesive piece 5 is preliminarily attached prior to the packaging of rice ball, the part 5' protrud ed from the wrapping end of the packaging sheet 4 can be automatically pasted to the outer surface of the cylindrical covering 7 simply by rolling the rice ball.