Described is a device for oxidizing a material comprising a material inlet port, a material outlet port and an oxidation zone extending therebeteween, the device comprising at least one nozzle unit (7, 8) for introducing a gasification agent arranged and/or configured such that the material is transported by the gasification means from the material inlet port through the oxidation unit (2) to the material outlet port. A multi-stage gasifier according to the invention, in particular a full stream gasifier, preferably comprises individual components in a simple, low-maintenance and slag-proof design, and can preferably optionally be upscaled. The produced synthesis gas can preferably be used for subsequent gas utilization without that a complex gas purification is required.
