Abstract: A pusher furnace for heating workpieces has an elongate and generally horizontally extending chamber housing a plurality of trays to receive workpieces thereon to be heated within the chamber. The chamber is divided into at least two generally parallel rows of a plurality of trays and pusher mechanisms are provided adjacent each end of the chamber to push the trays along the rows to circulate them within the chamber. In one embodiment, the chamber is divided into three rows of trays wherein a pusher mechanism alternately transfers work trays from one row to the other rows. Each work tray is provided with a plurality of opposed slots at the upper and lower surface thereof so that work engaging fingers can be inserted into the slots for engaging underneath the workpieces for transfer to and from the furnace.