A pellet press for producing pellets from material which is to be compressed. In the pellet press, the biomass is compressed through the holes of the die by at least one press device comprising a roller which rolls on the die, to form pellets. The die and/or the roller move in relation to each other during the production thereof. Provides essential machine elements or modules which are simple to access and also quick to exchange. The construction and operation of the pellet press should be modular so that the production power can be variably adjusted and/or the production is independent of the repairs of individual modules. At least one press device comprising at least one roller and/or the die is arranged inside a press frame in the pellet press, the press frame being embodied in the form of at least one C-frame and/or at least one window frame.