Thermal states of light are widely used in quantum optics due to their correlation properties. As is well known, their correlation properties and the photon-number distribution as a whole are strongly dependent on the mode number selected by the detection scheme. The same changes can be caused by photon subtraction. Therefore, we describe the general case of the multimode thermal state after a multiphoton subtraction, when the photon-number statistics is registered by the detector selecting a part of the initial modes. We present an analytical form of the obtained photon-number distribution and its general properties and check them in the experiment.