Based on the equivalent electric circuit of a cell, the equation for determination of the cell membrane permittance has been justified. The contactless method for measuring the permittance with the use of the inhomogeneous alternating electric field has been developed. The method consists in determination of the equilibrium frequency being a boundary frequency between zones of positive and negative dielectrophoresis in a cell. Human erythrocytes were used as the cells to be examined. The measurements showed that for intact erythrocytes the membrane permittance was constant in all the electrolytes used in the experiment and equal to (2.4 ± 0.5) 10-13 F, which was in a good agreement with the data obtained by other methods. The measurements of the membrane permittance of human erythrocytes depending on the parvovirus concentration demonstrated that the value of the membrane permittance could be used as a quantitative characteristic of the cell biological activity.