The paper presents the design of a multireflection time-of-flight mass analyzer wherein the ions are successively reflected from two parallel two-dimensional gridless electrostatic mirrors. The spatial confinement of an ion beam at numerous reflections and time focusing in a wide range of energies are achieved due to optimization of the field distribution at the mirrors. The analyzer is suitable for operation both in the high mass resolution mode and in the time-of-flight "slow" ion separation mode in tandem spectrometers.