FIELD: measuring. SUBSTANCE: invention relates to apparatuses for monitoring and measuring the physical parameters of substances. The crucible apparatus comprises a carrier metal container, a metal first cover located in the upper part of the above container, and fastening rods used to coaxially suspend the container and the first cover in the high-temperature heating area of a vertical electric furnace. A ceramic crucible with a melt is also coaxially placed in said container. The apparatus comprises a second axisymmetrical cover of a variable diameter, made of ceramics, in the upper part thereof made in the form of a washer placed at a distance H1 under the first cover. Said washer is installed coaxially on the upper part of the ceramic crucible. The second cover with the lower part thereof is placed inside the crucible and is made in the form of an axisymmetrical body with a diameter smaller compared to the upper part, with a height H2, the value whereof is greater than the above distance H1. The end of the lower part of the second cover is therein located above the melt in the crucible. EFFECT: reduction in the possibility of spilling of the examined melt from the crucible apparatus.