A surface mounting apparatus includes a conveyer supporting a printed wiring board being moved in a transportation direction, and a board transfer device that lowers a pair of tab members to positions spaced apart upstream and downstream of the printed wiring board and moves the tab members in the transportation direction. The board transfer device includes an interval changing device to change an interval between a pair of the tab members and a sensor to detect the position of the printed wiring board, an interference determination means to determine the absence or presence of the printed wiring board at the positions to which both the tab members are to be lowered according to the position of the printed wiring board detected by the sensor and interval setting means to move the tab members by driving the interval changing device according to a detection result of the interference determination means.