A fabrication method for a multi-piece board includes: checking whether pieces (printed wiring boards) are defect-free or not; forming a first recess in a joint portion between a defective piece and a frame; forming a first fitting portion at the frame by separating the defective piece; cutting out a defect-free piece having a second fitting portion from another board; forming a second recess in the second fitting portion; fitting the second fitting portion into the first fitting portion; flattening a joint portion; and filling an adhesive in a third recess which is formed by the first recess and the second recess, and curing the adhesive to adhere the frame and the defect-free piece.