Abstract: An apparatus for preparing a mixture, such as mortar, with predetermined quantities by weight of the components, such as sand, cement and the like, a supply of which is present in container compartments 4, 5 of e.g. hopper 1. The container compartments are each connectable to a metering conveyor 11, 12 of the apparatus. The apparatus is further provided with a mixing vessel 13 having stirring means, the vessel being supported at least partly on force absorbers 14 of weighing means. The weighting means are coupled with control means 15 for successively putting into operation the metering conveyor means for the various components.