A non-Equi atomic W₂₄Ta₂₄Nb₂₄Cr₁₆Al₁₂ high entropy alloy (HEA) was designed based on thermodynamic calculations in order to obtain a single Body Centered Cubic (BCC) structure. The HEA was further fabricated by using the vacuum arc melting technique. The structural analysis of the HEA revealed the formation of a single BCC phase with the lattice parameter of 3.259Å. The micrograph of the HEA revealed dendritic structure with inter-dendritic segregations. The thermal analysis confirmed that the HEA is quite stable at high temperature up to 1600̊C. The thermal expansion of the HEA was also very less at 1100̊C. The mechanical property such as the hardness of the HEA at room temperature was quiet high as 467 ± 20 HV₀.₅. The HEA was further heat treated at very high temperature (1000̊C) and the structural and mechanical properties were evaluated. The heat-treated HEA shows excellent structural stability as no secondary phases were formed in those samples. The mechanical property such as hardness of the HEA was increased continuously on increasing the heat treatment duration which shows that the current alloy is highly preferable for possible high temperature applications.