A purpose of the invention is to provide a powder supply device having a dust collection unit to collect powdery dust released when powder is supplied from a lateral side, and having a space-saving and simplified structure. A powder supply device according to the present invention has a main body, a plurality of stockers and a dust collection unit. The stocker has a charge port and a supplier. The dust collection unit has a casing, an exhauster and a filtering member. The casing has a ceiling portion and a lateral side portion, with a side opposing said ceiling portion being opened to form a lid-shaped configuration. The lateral side portion has a notched portion into which the supplier is to be inserted. The filtering member is provided inside the casing and is positioned above the notched portion and below the ceiling portion in order to collect the powder.