An analytical expression of the integral electrical conductivity of a semiconductor nanolayer, the charge carriers of which are located in a triangular quantum well, is obtained. The isoenergetic surface of the semiconductor material has the shape of a triaxial ellipsoid. The charge carrier behavior is described by the quantum Liouville equation. The dependence of electrical conductivity on dimensionless parameters is analyzed: the transverse electric field strength, the longitudinal electric field frequency, the charge carrier effective masses and the heterointerface specular coefficient. It is established that the conductivity of a triangular well compared to a rectangular well is more dependent on the effective mass, which to allow to select a material with the best high-frequency properties.