Molecular beam epitaxy has been used to grow thick epitaxial InAs onto (001) oriented SI-GaAs, under a wide range of substrate temperatures (T-s = 440-506 degrees C) and different V/III Bur ratios (phi As-4/phi In). Microstructure of epilayers was examined by high-resolution X-ray diffractometry. It has been found that full width at half maximum (FWHM) of the (004) rocking curves could be as low as about 120 arcsec when the layers mere grown at T-s = 506 degrees C and (phi As-4/phi pIn) approximate to 6. Transport properties of the layers have been investigated by Hall effect measurements in the magnetic field up to 1.5 T at temperatures from 3.5 to 300 K. It has been found that the properties of InAs are greatly influenced by the growth conditions, especially by substrate temperature during epitaxial process. Additionally all InAs layers exhibited characteristic maximum of Hall coefficient at temperatures of about 60 K, which is not typical for semiconductors. It is shown that assumption of existence of two additional levels allow to fit ail transport characteristics.