When a thin liquid layer, which is at rest under the action or gravity on a horizontal wall, is locally heated from below, a flow is induced in the layer by the surface-tension force. The flow in such a case is studied theoretically by using the Stokes approximation and the thin film approximation. This flow is governed by two dimensionless parameters, Nusselt number N and thermal Weber number M. When the liquid layer is heated from below, the free surface is always depressed. When the heating is strong, the liquid layer breaks up. The critical value of the thermal Weber number, above which the liquid layer breaks up, is found as a function of N. The shapes of the surface just when a breakup occurs are calculated. The critical thermal Weber numbers are experimentally found for the case of an oil sheet. These values are in agreement with the predictions from the theory.