The invention relates to a machining device (10) comprising at least one machining head (16) designed to provide at least one high-energy machining beam (22), especially an electron or laser beam. Such a machining device is used to remove material from workpieces (28) or for connecting workpieces (28) by bonding, especially by means of welding. According to the invention, at least one scanning device (32) designed as an optical coherence tomograph and provided for surface scanning is associated with the machining head (16). The invention also relates to a method for machining material using a high-energy machining beam for scanning surface areas of a workpiece which is machined, not yet machined, or being machined, by means of an optical coherence tomograph.