The invention discloses a heating furnace suitable for a Gieseler tester. The heating furnace comprises a furnace body, a furnace hearth, a thermoelectric couple and a furnace hearth cover, wherein a handle I, a center round hole, a movable cover and a groove are arranged on the furnace hearth cover; the center round hole vertically penetrates through a circle center of the furnace hearth cover; the handle I is arranged outside the center round hole which is formed in the furnace hearth cover; the movable cover is arranged on the furnace hearth cover; the center distance of the movable cover and the furnace hearth cover is small than that of the handle I and the furnace hearth cover; the groove is formed in the furnace hearth cover; and the thermoelectric couple is arranged in the groove. The heating furnace is simple in structure and convenient to use, can prevent solid/liquid in the furnace hearth from contacting air and from being oxidized, and improves the work efficiency of an experiment instrument and the accuracy and precision of an experiment at the same time.