An optical module for a machine for machining workpieces and/or for producing molded padding by position-selective solidification of material powder to form coherent regions by means of a focused laser beam, comprising: a housing with means for detachably attaching the optical module to the machine; a plurality of optical components (4, 14) arranged in or on the housing for collimating and focusing the laser beam; a collimating optical changer with a plurality of collimating optics; and an exchangeable focusing module with a focusing optic; characterized in that: the focusing module has at least two clamping bolts to connect said focusing module to corresponding receptacles on the housing of the optical module, the receptacles are operable electromagnetically, hydraulically or pneumatically or have clamping means which are adapted to be clamped by a spring; the optical module further comprises an automatically exchangeable powder nozzle, wherein the powder nozzle comprises a flange with at least two clamping bolts to connect said flange to corresponding receptacles on the housing of the optical module, wherein the receptacles comprise clamping mechanisms which are operable electromagnetically, hydraulically or pneumatically or which have clamping means, which are adapted to be clamped by a spring, and a cylindrical recess for the focusing module is formed inside the flange so that a lower end of the focusing module is located inside the recess in the powder nozzle, wherein the focusing module and the powder nozzle are arranged coaxially with respect to each other and with respect to the laser beam on the optical module. a housing with means for detachably attaching the optical module to the machine; a plurality of optical components (4, 14) arranged in or on the housing for collimating and focusing the laser beam; a collimating optical changer with a plurality of collimating optics; and an exchangeable focusing module with a focusing optic; characterized in that: the focusing module has at least two clamping bolts to connect said focusing module to corresponding receptacles on the housing of the optical module, the receptacles are operable electromagnetically, hydraulically or pneumatically or have clamping means which are adapted to be clamped by a spring; the optical module further comprises an automatically exchangeable powder nozzle, wherein the powder nozzle comprises a flange with at least two clamping bolts to connect said flange to corresponding receptacles on the housing of the optical module, wherein the receptacles comprise clamping mechanisms which are operable electromagnetically, hydraulically or pneumatically or which have clamping means, which are adapted to be clamped by a spring, and a cylindrical recess for the focusing module is formed inside the flange so that a lower end of the focusing module is located inside the recess in the powder nozzle, wherein the focusing module and the powder nozzle are arranged coaxially with respect to each other and with respect to the laser beam on the optical module. the focusing module has at least two clamping bolts to connect said focusing module to corresponding receptacles on the housing of the optical module, the receptacles are operable electromagnetically, hydraulically or pneumatically or have clamping means which are adapted to be clamped by a spring; the optical module further comprises an automatically exchangeable powder nozzle, wherein the powder nozzle comprises a flange with at least two clamping bolts to connect said flange to corresponding receptacles on the housing of the optical module, wherein the receptacles comprise clamping mechanisms which are operable electromagnetically, hydraulically or pneumatically or which have clamping means, which are adapted to be clamped by a spring, and a cylindrical recess for the focusing module is formed inside the flange so that a lower end of the focusing module is located inside the recess in the powder nozzle, wherein the focusing module and the powder nozzle are arranged coaxially with respect to each other and with respect to the laser beam on the optical module.