Provided are a stud supply device and a stud supply method with which a stud can be supplied to a welding electrode in the correct orientation. The stud supply device comprises: a magazine in which a predetermined number of studs can be aligned and stored in series inside a magazine hole from a stop part to one end side; switching mechanisms having a plurality of balls that can move between a position contacting the studs and a position not contacting the studs, and a reciprocating member that restricts the movement of the plurality of balls, the switching mechanisms switching between a state in which the studs are stopped at the stop part and a state in which the studs are allowed to pass; and a first air injection part that is provided more on the one end side than the stop part, and that injects air from the one end side to the stud stopped at the stop part.