Two by two MIMO antenna composed of two inverted L antennas is proposed and numerically analyzed. Inverted L antenna formed by coplanar waveguide is printed on the dielectric substrate. The thickness of dielectric substrate is 3 mm, its relative permittivity is 2.6 and the loss tangent is 0.0022. When the size of dielectric substrate is 41.5 mm by 40 mm, the S11 less than −10 dB is satisfied from 2.41 GHz to 2.49 GHz. The distance between two antennas is 36.1 mm. The S21 less than −20 dB and the correlation coefficient less than 0.005 are satisfied from 2.4 GHz to 2.5 GHz. The calculated directivity is 3.23 dBi at 2.45 GHz. In the numerical analysis, the electromagnetic simulator WIPL-D based on the Method of Moments is used.