  The probability of the detection of Earth-like exoplanets may increase in the
near future after the launch of the space missions using the transit photometry
as observation method. By using this technique only the semi-major axis of the
detected planet can be determined, and there will be no information on the
upper limit of its orbital eccentricity. However, the orbital eccentricity is a
very important parameter, not only from a dynamical point of view, since it
gives also information on the climate and the habitability of the Earth-like
planets. In this paper a possible procedure is suggested for confining the
eccentricity of an exoplanet discovered by transit photometry if an already
known giant planet orbits also in the system.
