To surely solder a wide land part to an electronic circuit unit by providing the wide land part and a narrow land part connected to it with a solder resist formed on the surface of a printed board.

A printed board 1 which is to be a motherboard comprises a conductive pattern 2 formed on its surface and a plurality of land parts 3 which are, formed at an end part of the conductive pattern 2, for soldering. The solder resist 4 is printed on the surface of the printed board 3 comprising the conductive pattern 2 and the land part 3, with a square wide land part 3a exposed above the solder resist 4 and a plurality of narrow land parts 3b which are exposed above the solder resist 4 and connected to the wide land part 3a formed as well. Thus, a solder positioned at the narrow land part 3b is drawn to the wide land part 3a, increasing the amount of the solder at the wide land part 3a.