Provided are a tray feeder which provides parts to a part mounting device and parts providing method using the same. The tray feeder includes: a magazine which houses at least one tray for accommodating parts; an inserting/extracting member which inserts a tray into the magazine or extracts a tray from the magazine; a buffer member which is positioned above the magazine and supports a standby tray from which parts accommodated therein are to be mounted on a board by a part mounting device; and a feeding member which is positioned above the inserting/extracting member and provides a tray supported by the feeding member so that parts accommodated in the supported tray are adhered by the part mounting device, wherein the inserting/extracting member is elevated or lowered to insert a tray into the magazine or extract a tray from the magazine.