To produce a sandwich of slightly vinegared rice with laver having an excellent appearance with the whole flat surface just like a sandwich by a bread and a sandwich of a rice ball.

Laminar boiled rice 3 and 3' of fixed length with a space between them packed with an ingredient 2 in the length direction at the center is prepared, laver sheets 4 and 4' through which air-permeable holes 4a and 4a' are bored in the all surfaces are stuck to both sides of the top and bottom of each of laminar boiled rice 3 and 3', the slightly vinegared rice is pressed, formed into a laminar slightly vinegared rice body 1a with laver having a quandrangular cross section, the laminar slightly vinegared rice body 1a is cut in its width direction at fixed intervals, divided into approximately square small pieces 1b, then the square small pieces are slantingly cut to give a triangular sandwich of slightly vinegared rice and a sandwich A of a rice ball.