A board printing apparatus comprising: a board working table (2a, 2b) including a first board working table and a second board working table holding a board to be printed on; a first printing table and a second printing table aligned in a prescribed direction in a horizontal direction above the board working table; and a control portion controlling printing operations of the first printing table and the second printing table, wherein the first printing table holds a small component mask having a first thickness configured to perform first printing to print a viscous material on the board, the second printing table holds a large component mask having a second thickness thicker than the first thickness, formed with a relief portion having a depth larger than the first thickness on a board contact surface to relieve the viscous material printed by the small component mask, configured to perform second printing to print the viscous material on the board after the first printing performed by the first printing table, and the board working table and at least one of the first printing table and the second printing table are configured to be movable in a vertical direction, and the control portion is configured to perform the first printing on the board held by the board working table by the small component mask of the first printing table and to perform the second printing on the board held by the board working table by the large component mask of the second printing table after the first printing performed on the board, characterized in that the control portion is configured to perform a board printing operation of the second printing by the second printing table and the second board working table during a board printing operation of the first printing performed by the first printing table and the first board working table, and the board working table and the second printing table are configured to be movable in the prescribed direction in the horizontal direction so that position coordinates of the board and the large component mask in the prescribed direction are aligned by a movement of the board working table in the prescribed direction and a movement of the second printing table in the prescribed direction. a board working table (2a, 2b) including a first board working table and a second board working table holding a board to be printed on; a first printing table and a second printing table aligned in a prescribed direction in a horizontal direction above the board working table; and a control portion controlling printing operations of the first printing table and the second printing table, wherein the first printing table holds a small component mask having a first thickness configured to perform first printing to print a viscous material on the board, the second printing table holds a large component mask having a second thickness thicker than the first thickness, formed with a relief portion having a depth larger than the first thickness on a board contact surface to relieve the viscous material printed by the small component mask, configured to perform second printing to print the viscous material on the board after the first printing performed by the first printing table, and the board working table and at least one of the first printing table and the second printing table are configured to be movable in a vertical direction, and the control portion is configured to perform the first printing on the board held by the board working table by the small component mask of the first printing table and to perform the second printing on the board held by the board working table by the large component mask of the second printing table after the first printing performed on the board, characterized in that the control portion is configured to perform a board printing operation of the second printing by the second printing table and the second board working table during a board printing operation of the first printing performed by the first printing table and the first board working table, and the board working table and the second printing table are configured to be movable in the prescribed direction in the horizontal direction so that position coordinates of the board and the large component mask in the prescribed direction are aligned by a movement of the board working table in the prescribed direction and a movement of the second printing table in the prescribed direction.