The aim of the invention is to design a bulk-material cooler, particularly one for cooling cement clinker, which operates according to the walking floor principle, so that its cooling grate can be composed of a multitude of ventilated cooling grate modules, which can be assembled in an easy and variable manner, in order to obtain large lengths and widths of the cooler. When these cooling grate modules move between an advancing and returning position, even lateral and/or height offset of the guiding elements can be compensated for in a kinematic manner. To this end, the invention provides that the cooling grate, when viewed over the length and width of the cooler, is composed of a multitude of modules (13, 14) ventilated with cooling air. The coupling of the cooling grate modules of each longitudinal row of cooling grate modules is effected by an articulated joint.