To make the work efficient without staining the backside when substrates for various electronic parts are subjected to heating treatment and ultraviolet ray treatment.

From the entrance side 2 to the exit side 3 of a furnace body 1 a conveyance rope 8 is stretched in a manner of lengthwise splitting the inside and outside of the furnace body 1. To a frame 9 which supports the conveyance rope 8 in front and in rear a moving means is attached in such a manner as to make the conveyance rope 8 movable up and down and back and forth in relation to the furnace body 1. An electronic-part substrate to be treated is deposited on the conveyance rope 8 and conveyed into and out of the furnace.