Selective wet etching technique was applied to commercial ( ) β-Ga₂O₃  single crystal substrates. Some etching recipes allowed us to reveal sharp etch pits on the surface of the substrates. The geometric shape, orientation and density of etch pits were investigated in as-delivered specimens. An observation of mutual location of the etch pits indicates the likely formation low-angle grain boundaries that can form upon heating. Selective wet etching technique was applied to commercial ( ) β-Ga₂O₃   single crystal substrates. Some etching recipes allowed us to reveal sharp etch pits on the surface of the substrates. The geometric shape, orientation and density of etch pits were investigated in as-delivered specimens. An observation of mutual location of the etch pits indicates the likely formation low-angle grain boundaries that can form upon heating.