Using the simple diagrammatic relationship of general solution of the TEM00?thermo-insensitive resonator, the circle in the place of thermo-perturbation lens is tangent to circle 1 of the mirror R1 of the resonator. A very simple design and calculation method of such resonator has been proposed. And as an example, the design and calculation of four types of the TEMoo-thermo-insensitive resonators have been presented.